diff --git a/include/cantera/kinetics/Kinetics.h b/include/cantera/kinetics/Kinetics.h
index 5a7ef34ee..1b48970fd 100644
--- a/include/cantera/kinetics/Kinetics.h
+++ b/include/cantera/kinetics/Kinetics.h
@@ -146,7 +146,7 @@ public:
      *  replacing:
      *
      *  - ThermoPhase::id()
-     *  - ThermoPhase::eosType()
+     *  - ThermoPhase::type()
      *  - ThermoPhase::nSpecies()
      *
      *  @param tpVector Vector of pointers to ThermoPhase objects. this is the
diff --git a/include/cantera/thermo/ConstDensityThermo.h b/include/cantera/thermo/ConstDensityThermo.h
index 7c9f5537e..7857da5f6 100644
--- a/include/cantera/thermo/ConstDensityThermo.h
+++ b/include/cantera/thermo/ConstDensityThermo.h
@@ -36,8 +36,10 @@ public:
     ConstDensityThermo& operator=(const ConstDensityThermo& right);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
-    //! Returns a constant corresponding to this class's equation of state
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "ConstDensity";
+    }
 
     virtual doublereal enthalpy_mole() const;
     virtual doublereal entropy_mole() const;
diff --git a/include/cantera/thermo/DebyeHuckel.h b/include/cantera/thermo/DebyeHuckel.h
index 6f22e3b57..e8e984776 100644
--- a/include/cantera/thermo/DebyeHuckel.h
+++ b/include/cantera/thermo/DebyeHuckel.h
@@ -591,6 +591,9 @@ public:
     //! @{
 
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "DebyeHuckel";
+    }
 
     //! @}
     //! @name  Molar Thermodynamic Properties of the Solution
diff --git a/include/cantera/thermo/EdgePhase.h b/include/cantera/thermo/EdgePhase.h
index a0c1b3b3d..0cd4004a4 100644
--- a/include/cantera/thermo/EdgePhase.h
+++ b/include/cantera/thermo/EdgePhase.h
@@ -39,10 +39,14 @@ public:
     EdgePhase& operator=(const EdgePhase& right);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
-    //! returns the equation of state type
     virtual int eosType() const {
+        warn_deprecated("EdgePhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cEdge;
     }
+    virtual std::string type() const {
+        return "Edge";
+    }
 
     //! Set the Equation-of-State parameters by reading an XML Node Input
     /*!
diff --git a/include/cantera/thermo/FixedChemPotSSTP.h b/include/cantera/thermo/FixedChemPotSSTP.h
index c8fad71f6..215c299ff 100644
--- a/include/cantera/thermo/FixedChemPotSSTP.h
+++ b/include/cantera/thermo/FixedChemPotSSTP.h
@@ -190,8 +190,12 @@ public:
      * Equation of state flag.
      *
      * Returns the value cStoichSubstance, defined in mix_defs.h.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "FixedChemPot";
+    }
 
     //! @}
     //! @name Mechanical Equation of State
diff --git a/include/cantera/thermo/HMWSoln.h b/include/cantera/thermo/HMWSoln.h
index cb039a803..62afd272d 100644
--- a/include/cantera/thermo/HMWSoln.h
+++ b/include/cantera/thermo/HMWSoln.h
@@ -1216,6 +1216,9 @@ public:
     //! @{
 
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "HMWSoln";
+    }
 
     //! @}
     //! @name  Molar Thermodynamic Properties of the Solution
diff --git a/include/cantera/thermo/IdealGasPhase.h b/include/cantera/thermo/IdealGasPhase.h
index f945d1dd4..759346756 100644
--- a/include/cantera/thermo/IdealGasPhase.h
+++ b/include/cantera/thermo/IdealGasPhase.h
@@ -315,10 +315,16 @@ public:
     //! Equation of state flag.
     /*!
      * Returns the value cIdealGas, defined in mix_defs.h.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const {
+        warn_deprecated("IdealGasPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cIdealGas;
     }
+    virtual std::string type() const {
+        return "IdealGas";
+    }
 
     //! @name Molar Thermodynamic Properties of the Solution
     //! @{
diff --git a/include/cantera/thermo/IdealMolalSoln.h b/include/cantera/thermo/IdealMolalSoln.h
index 616f3af01..ab4e5383e 100644
--- a/include/cantera/thermo/IdealMolalSoln.h
+++ b/include/cantera/thermo/IdealMolalSoln.h
@@ -114,6 +114,10 @@ public:
      */
     IdealMolalSoln(XML_Node& phaseRef, const std::string& id = "");
 
+    virtual std::string type() const {
+        return "IdealMolalSoln";
+    }
+
     //! @}
     //! @name  Molar Thermodynamic Properties of the Solution
     //! @{
diff --git a/include/cantera/thermo/IdealSolidSolnPhase.h b/include/cantera/thermo/IdealSolidSolnPhase.h
index dacfc8cde..82a5f6169 100644
--- a/include/cantera/thermo/IdealSolidSolnPhase.h
+++ b/include/cantera/thermo/IdealSolidSolnPhase.h
@@ -22,6 +22,7 @@ namespace Cantera
 
 /*!
  * @name CONSTANTS - Models for the Standard State of IdealSolidSolnPhase's
+ * @deprecated To be removed after Cantera 2.3.
  */
 //@{
 const int cIdealSolidSolnPhase0 = 5010;
@@ -99,8 +100,12 @@ public:
     /**
      * Equation of state flag. Returns a value depending upon the value of
      * #m_formGC, which is defined at instantiation.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "IdealSolidSoln";
+    }
 
     //! @name Molar Thermodynamic Properties of the Solution
     //! @{
diff --git a/include/cantera/thermo/IdealSolnGasVPSS.h b/include/cantera/thermo/IdealSolnGasVPSS.h
index c097e6525..bc88328f4 100644
--- a/include/cantera/thermo/IdealSolnGasVPSS.h
+++ b/include/cantera/thermo/IdealSolnGasVPSS.h
@@ -21,6 +21,7 @@ namespace Cantera
 /*!
   * @name CONSTANTS
   * Models for the Standard State of an IdealSolnPhase
+  * @deprecated To be removed after Cantera 2.3.
   */
 //@{
 const int cIdealSolnGasPhaseG = 6009;
@@ -56,6 +57,9 @@ public:
     //@{
 
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "IdealSolnGas";
+    }
 
     //! @}
     //! @name Molar Thermodynamic Properties
diff --git a/include/cantera/thermo/IonsFromNeutralVPSSTP.h b/include/cantera/thermo/IonsFromNeutralVPSSTP.h
index f4bf2aad6..1d1402a83 100644
--- a/include/cantera/thermo/IonsFromNeutralVPSSTP.h
+++ b/include/cantera/thermo/IonsFromNeutralVPSSTP.h
@@ -156,6 +156,10 @@ public:
     //! @{
 
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "IonsFromNeutral";
+    }
+
 
     //! @}
     //! @name Molar Thermodynamic Properties
diff --git a/include/cantera/thermo/LatticePhase.h b/include/cantera/thermo/LatticePhase.h
index 8d79fdecb..99bb3d436 100644
--- a/include/cantera/thermo/LatticePhase.h
+++ b/include/cantera/thermo/LatticePhase.h
@@ -253,9 +253,15 @@ public:
     LatticePhase(XML_Node& phaseRef, const std::string& id = "");
 
     //! Equation of state flag. Returns the value cLattice
+    //! @deprecated To be removed after Cantera 2.3.
     virtual int eosType() const {
+        warn_deprecated("LatticePhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cLattice;
     }
+    virtual std::string type() const {
+        return "Lattice";
+    }
 
     //! @name Molar Thermodynamic Properties of the Solution
     //! @{
diff --git a/include/cantera/thermo/LatticeSolidPhase.h b/include/cantera/thermo/LatticeSolidPhase.h
index d835b8a9b..429e45965 100644
--- a/include/cantera/thermo/LatticeSolidPhase.h
+++ b/include/cantera/thermo/LatticeSolidPhase.h
@@ -115,10 +115,16 @@ public:
     //! Equation of state type flag.
     /*!
      *  Returns cLatticeSolid, listed in mix_defs.h.
+     *  @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const {
+        warn_deprecated("LatticeSolidPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cLatticeSolid;
     }
+    virtual std::string type() const {
+        return "LatticeSolid";
+    }
 
     virtual doublereal minTemp(size_t k = npos) const;
     virtual doublereal maxTemp(size_t k = npos) const;
diff --git a/include/cantera/thermo/MargulesVPSSTP.h b/include/cantera/thermo/MargulesVPSSTP.h
index 120ce3e26..709025a3b 100644
--- a/include/cantera/thermo/MargulesVPSSTP.h
+++ b/include/cantera/thermo/MargulesVPSSTP.h
@@ -246,6 +246,10 @@ public:
     MargulesVPSSTP& operator=(const MargulesVPSSTP& b);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
+    virtual std::string type() const {
+        return "Margules";
+    }
+
     //! @name  Molar Thermodynamic Properties
     //! @{
 
diff --git a/include/cantera/thermo/MaskellSolidSolnPhase.h b/include/cantera/thermo/MaskellSolidSolnPhase.h
index 159044382..67b0a3b10 100644
--- a/include/cantera/thermo/MaskellSolidSolnPhase.h
+++ b/include/cantera/thermo/MaskellSolidSolnPhase.h
@@ -35,6 +35,10 @@ public:
     MaskellSolidSolnPhase& operator=(const MaskellSolidSolnPhase&);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
+    virtual std::string type() const {
+        return "MaskellSolidsoln";
+    }
+
     virtual void getActivityConcentrations(doublereal* c) const;
     virtual doublereal standardConcentration(size_t k=0) const { return 1.0; }
     virtual doublereal logStandardConc(size_t k=0) const { return 0.0; }
diff --git a/include/cantera/thermo/MetalPhase.h b/include/cantera/thermo/MetalPhase.h
index 369df4b67..d6867f21b 100644
--- a/include/cantera/thermo/MetalPhase.h
+++ b/include/cantera/thermo/MetalPhase.h
@@ -44,8 +44,13 @@ public:
     // Overloaded methods of class ThermoPhase
 
     virtual int eosType() const {
+        warn_deprecated("MetalPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cMetal;
     }
+    virtual std::string type() const {
+        return "Metal";
+    }
 
     virtual doublereal enthalpy_mole() const {
         return 0.0;
diff --git a/include/cantera/thermo/MetalSHEelectrons.h b/include/cantera/thermo/MetalSHEelectrons.h
index b87ed3aa1..b7808ec26 100644
--- a/include/cantera/thermo/MetalSHEelectrons.h
+++ b/include/cantera/thermo/MetalSHEelectrons.h
@@ -204,8 +204,12 @@ public:
      * Equation of state flag.
      *
      * Returns the value cMetalSHEelectrons, defined in mix_defs.h.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "MetalSHEelectrons";
+    }
 
     //! @name Mechanical Equation of State
     //! @{
diff --git a/include/cantera/thermo/MineralEQ3.h b/include/cantera/thermo/MineralEQ3.h
index de187c4cc..0378b423f 100644
--- a/include/cantera/thermo/MineralEQ3.h
+++ b/include/cantera/thermo/MineralEQ3.h
@@ -119,8 +119,12 @@ public:
      * Equation of state flag.
      *
      * Returns the value cStoichSubstance, defined in mix_defs.h.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "MineralEQ3";
+    }
 
     //! @name Mechanical Equation of State
     //! @{
diff --git a/include/cantera/thermo/MixedSolventElectrolyte.h b/include/cantera/thermo/MixedSolventElectrolyte.h
index adf3fc472..6ceb03236 100644
--- a/include/cantera/thermo/MixedSolventElectrolyte.h
+++ b/include/cantera/thermo/MixedSolventElectrolyte.h
@@ -238,6 +238,10 @@ public:
     MixedSolventElectrolyte& operator=(const MixedSolventElectrolyte& b);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
+    virtual std::string type() const {
+        return "MixedSolventElectrolyte";
+    }
+
     //! @name  Molar Thermodynamic Properties
     //! @{
 
diff --git a/include/cantera/thermo/MixtureFugacityTP.h b/include/cantera/thermo/MixtureFugacityTP.h
index 99db095cb..c2f1fd809 100644
--- a/include/cantera/thermo/MixtureFugacityTP.h
+++ b/include/cantera/thermo/MixtureFugacityTP.h
@@ -82,6 +82,10 @@ public:
     //! @name  Utilities
     //! @{
 
+    virtual std::string type() const {
+        return "MixtureFugacity";
+    }
+
     virtual int standardStateConvention() const;
 
     //! Set the solution branch to force the ThermoPhase to exist on one branch
diff --git a/include/cantera/thermo/MolarityIonicVPSSTP.h b/include/cantera/thermo/MolarityIonicVPSSTP.h
index 2a2af1645..e53c7a97e 100644
--- a/include/cantera/thermo/MolarityIonicVPSSTP.h
+++ b/include/cantera/thermo/MolarityIonicVPSSTP.h
@@ -74,6 +74,10 @@ public:
     MolarityIonicVPSSTP& operator=(const MolarityIonicVPSSTP& b);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
+    virtual std::string type() const {
+        return "MolarityIonic";
+    }
+
     /**
      * @name Activities, Standard States, and Activity Concentrations
      *
diff --git a/include/cantera/thermo/PhaseCombo_Interaction.h b/include/cantera/thermo/PhaseCombo_Interaction.h
index df2fd3f8d..d2fb1b0c1 100644
--- a/include/cantera/thermo/PhaseCombo_Interaction.h
+++ b/include/cantera/thermo/PhaseCombo_Interaction.h
@@ -335,6 +335,9 @@ public:
     //! @{
 
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "PhaseCombo_Interaction";
+    }
 
     //! @}
     //! @name  Molar Thermodynamic Properties
diff --git a/include/cantera/thermo/PureFluidPhase.h b/include/cantera/thermo/PureFluidPhase.h
index 000c439d0..43fadc281 100644
--- a/include/cantera/thermo/PureFluidPhase.h
+++ b/include/cantera/thermo/PureFluidPhase.h
@@ -38,9 +38,15 @@ public:
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
     //! Equation of state type
+    //! @deprecated To be removed after Cantera 2.3.
     virtual int eosType() const {
+        warn_deprecated("PureFluidPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cPureFluid;
     }
+    virtual std::string type() const {
+        return "PureFluid";
+    }
 
     virtual doublereal enthalpy_mole() const;
     virtual doublereal intEnergy_mole() const;
diff --git a/include/cantera/thermo/RedlichKisterVPSSTP.h b/include/cantera/thermo/RedlichKisterVPSSTP.h
index b2e149a33..24bda80e6 100644
--- a/include/cantera/thermo/RedlichKisterVPSSTP.h
+++ b/include/cantera/thermo/RedlichKisterVPSSTP.h
@@ -247,6 +247,10 @@ public:
     RedlichKisterVPSSTP& operator=(const RedlichKisterVPSSTP& b);
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
+    virtual std::string type() const {
+        return "RedlichKister";
+    }
+
     //! @name  Molar Thermodynamic Properties
     //! @{
 
diff --git a/include/cantera/thermo/RedlichKwongMFTP.h b/include/cantera/thermo/RedlichKwongMFTP.h
index e0710350e..7e06b9b06 100644
--- a/include/cantera/thermo/RedlichKwongMFTP.h
+++ b/include/cantera/thermo/RedlichKwongMFTP.h
@@ -50,6 +50,9 @@ public:
     virtual ThermoPhase* duplMyselfAsThermoPhase() const;
 
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "RedlichKwong";
+    }
 
     //! @name Molar Thermodynamic properties
     //! @{
diff --git a/include/cantera/thermo/SemiconductorPhase.h b/include/cantera/thermo/SemiconductorPhase.h
index 9364ac996..b0030d97f 100644
--- a/include/cantera/thermo/SemiconductorPhase.h
+++ b/include/cantera/thermo/SemiconductorPhase.h
@@ -53,8 +53,13 @@ public:
     // Overloaded methods of class ThermoPhase
 
     virtual int eosType() const {
+        warn_deprecated("SemiconductorPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cSemiconductor;
     }
+    virtual std::string type() const {
+        return "Semiconductor";
+    }
 
     virtual void setPressure(doublereal pres) {
         m_press = pres;
diff --git a/include/cantera/thermo/SingleSpeciesTP.h b/include/cantera/thermo/SingleSpeciesTP.h
index ac7c07fa0..19e072616 100644
--- a/include/cantera/thermo/SingleSpeciesTP.h
+++ b/include/cantera/thermo/SingleSpeciesTP.h
@@ -68,8 +68,12 @@ public:
      * Returns the equation of state type flag. This is a modified base class.
      * Therefore, if not overridden in derived classes, this call will throw an
      * exception.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "SingleSpecies";
+    }
 
     /**
      * @name  Molar Thermodynamic Properties of the Solution
diff --git a/include/cantera/thermo/StoichSubstance.h b/include/cantera/thermo/StoichSubstance.h
index 8fb4973b1..be9bdaefd 100644
--- a/include/cantera/thermo/StoichSubstance.h
+++ b/include/cantera/thermo/StoichSubstance.h
@@ -179,8 +179,12 @@ public:
      * Equation of state flag.
      *
      * Returns the value cStoichSubstance, defined in mix_defs.h.
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const;
+    virtual std::string type() const {
+        return "StoichSubstance";
+    }
 
     //! @name Mechanical Equation of State
     //! @{
diff --git a/include/cantera/thermo/SurfPhase.h b/include/cantera/thermo/SurfPhase.h
index c902be9e9..6ab818f68 100644
--- a/include/cantera/thermo/SurfPhase.h
+++ b/include/cantera/thermo/SurfPhase.h
@@ -172,10 +172,16 @@ public:
     //! Equation of state type flag.
     /*!
      *  Redefine this to return cSurf, listed in mix_defs.h.
+     *  @deprecated To be removed after Cantera 2.3.
      */
     virtual int eosType() const {
+        warn_deprecated("SurfPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return cSurf;
     }
+    virtual std::string type() const {
+        return "Surf";
+    }
 
     //! Return the Molar Enthalpy. Units: J/kmol.
     /*!
diff --git a/include/cantera/thermo/ThermoFactory.h b/include/cantera/thermo/ThermoFactory.h
index 1f8fe5bdd..b506970ef 100644
--- a/include/cantera/thermo/ThermoFactory.h
+++ b/include/cantera/thermo/ThermoFactory.h
@@ -110,6 +110,7 @@ inline ThermoPhase* newThermoPhase(const std::string& model,
  *  @param ieos  eosType id of the phase. This is unique for the phase
  *  @param length maximum length of the return string. Defaults to 100
  *  @returns a string representation of the eosType id for a phase
+ *  @deprecated To be removed after Cantera 2.3.
  */
 std::string eosTypeString(int ieos, int length = 100);
 
diff --git a/include/cantera/thermo/ThermoPhase.h b/include/cantera/thermo/ThermoPhase.h
index 09ed9c72c..5f4a230ec 100644
--- a/include/cantera/thermo/ThermoPhase.h
+++ b/include/cantera/thermo/ThermoPhase.h
@@ -119,11 +119,21 @@ public:
      * The base class returns zero. Subclasses should define this to return a
      * unique non-zero value. Constants defined for this purpose are listed in
      * mix_defs.h.
+     * @deprecated To be removed after Cantera 2.3. Use `type()` instead.
      */
     virtual int eosType() const {
+        warn_deprecated("ThermoPhase::eosType",
+                        "To be removed after Cantera 2.3.");
         return 0;
     }
 
+    //! String indicating the thermodynamic model implemented. Usually
+    //! corresponds to the name of the derived class, less any suffixes such as
+    //! "Phase", TP", "VPSS", etc.
+    virtual std::string type() const {
+        return "ThermoPhase";
+    }
+
     /**
      * Returns the reference pressure in Pa. This function is a wrapper
      * that calls the species thermo refPressure function.
diff --git a/include/cantera/thermo/WaterSSTP.h b/include/cantera/thermo/WaterSSTP.h
index 3196bc61f..5eb361e18 100644
--- a/include/cantera/thermo/WaterSSTP.h
+++ b/include/cantera/thermo/WaterSSTP.h
@@ -137,8 +137,13 @@ public:
     explicit WaterSSTP(XML_Node& phaseRef, const std::string& id = "");
 
     virtual int eosType() const {
+        warn_deprecated("WaterSSTP::eosType",
+                        "To be removed after Cantera 2.3.");
         return -1;
     }
+    virtual std::string type() const {
+        return "Water";
+    }
 
     //! @name  Molar Thermodynamic Properties of the Solution
     //! @{
diff --git a/include/cantera/thermo/electrolytes.h b/include/cantera/thermo/electrolytes.h
index 3de16ca46..f523a39d5 100644
--- a/include/cantera/thermo/electrolytes.h
+++ b/include/cantera/thermo/electrolytes.h
@@ -37,6 +37,7 @@ const int cEST_nonpolarNeutral = 5; // Nonpolar neutral species. These
 
 /**
  *  eosTypes returned for this ThermoPhase Object
+ *  @deprecated To be removed after Cantera 2.3.
  */
 const int cHMWSoln0 = 45010;
 const int cHMWSoln1 = 45011;
@@ -44,6 +45,7 @@ const int cHMWSoln2 = 45012;
 
 /**
  *  eosTypes returned for this ThermoPhase Object
+ *  @deprecated To be removed after Cantera 2.3.
  */
 const int cDebyeHuckel0 = 46010;
 const int cDebyeHuckel1 = 46011;
diff --git a/include/cantera/thermo/mix_defs.h b/include/cantera/thermo/mix_defs.h
index d62224870..f4a9a1b56 100644
--- a/include/cantera/thermo/mix_defs.h
+++ b/include/cantera/thermo/mix_defs.h
@@ -31,6 +31,7 @@ const int cHarmonicOsc = 4;
  * listed below. The Cantera Kernel however, will not be know about the class
  * and will therefore not be able to initialize the class within its "factory"
  * routines.
+ * @deprecated To be removed after Cantera 2.3.
  */
 const int cIdealGas = 1; // IdealGasPhase in IdealGasPhase.h
 const int cIncompressible = 2; // ConstDensityThermo in ConstDensityThermo.h
diff --git a/interfaces/cython/cantera/_cantera.pxd b/interfaces/cython/cantera/_cantera.pxd
index 5f177fe6a..abe0b90b3 100644
--- a/interfaces/cython/cantera/_cantera.pxd
+++ b/interfaces/cython/cantera/_cantera.pxd
@@ -43,10 +43,6 @@ cdef extern from "cantera/base/global.h" namespace "Cantera":
     cdef void Cxx_make_deprecation_warnings_fatal "Cantera::make_deprecation_warnings_fatal" ()
 
 cdef extern from "cantera/thermo/mix_defs.h":
-    cdef int thermo_type_ideal_gas "Cantera::cIdealGas"
-    cdef int thermo_type_surf "Cantera::cSurf"
-    cdef int thermo_type_edge "Cantera::cEdge"
-
     cdef int kinetics_type_gas "Cantera::cGasKinetics"
     cdef int kinetics_type_interface "Cantera::cInterfaceKinetics"
     cdef int kinetics_type_edge "Cantera::cEdgeKinetics"
@@ -108,7 +104,7 @@ cdef extern from "cantera/thermo/ThermoPhase.h" namespace "Cantera":
         CxxThermoPhase()
 
         # miscellaneous
-        int eosType()
+        string type()
         string report(cbool, double) except +
         string name()
         void setName(string)
diff --git a/interfaces/cython/cantera/onedim.pyx b/interfaces/cython/cantera/onedim.pyx
index b88dc6afe..1e604e5cb 100644
--- a/interfaces/cython/cantera/onedim.pyx
+++ b/interfaces/cython/cantera/onedim.pyx
@@ -466,7 +466,7 @@ cdef class _FlowBase(Domain1D):
 
 
 cdef CxxIdealGasPhase* getIdealGasPhase(ThermoPhase phase) except *:
-    if phase.thermo.eosType() != thermo_type_ideal_gas:
+    if pystr(phase.thermo.type()) != "IdealGas":
         raise TypeError('ThermoPhase object is not an IdealGasPhase')
     return <CxxIdealGasPhase*>(phase.thermo)
 
diff --git a/interfaces/cython/cantera/thermo.pyx b/interfaces/cython/cantera/thermo.pyx
index ee398c16b..291e68b4f 100644
--- a/interfaces/cython/cantera/thermo.pyx
+++ b/interfaces/cython/cantera/thermo.pyx
@@ -1219,7 +1219,7 @@ cdef class ThermoPhase(_SolutionBase):
 cdef class InterfacePhase(ThermoPhase):
     """ A class representing a surface or edge phase"""
     def __cinit__(self, *args, **kwargs):
-        if self.thermo.eosType() not in (thermo_type_surf, thermo_type_edge):
+        if pystr(self.thermo.type()) not in ("Surf", "Edge"):
             raise TypeError('Underlying ThermoPhase object is of the wrong type.')
         self.surf = <CxxSurfPhase*>(self.thermo)
 
diff --git a/src/equil/vcs_MultiPhaseEquil.cpp b/src/equil/vcs_MultiPhaseEquil.cpp
index 2237e1c93..ae99b77f9 100644
--- a/src/equil/vcs_MultiPhaseEquil.cpp
+++ b/src/equil/vcs_MultiPhaseEquil.cpp
@@ -715,8 +715,8 @@ int vcs_Cantera_to_vprob(MultiPhase* mphase, VCS_PROB* vprob)
         size_t nelem = tPhase->nElements();
 
         // Query Cantera for the equation of state type of the current phase.
-        int eos = tPhase->eosType();
-        bool gasPhase = (eos == cIdealGas);
+        std::string eos = tPhase->type();
+        bool gasPhase = (eos == "IdealGas");
 
         // Find out the number of species in the phase
         size_t nSpPhase = tPhase->nSpecies();
@@ -747,36 +747,22 @@ int vcs_Cantera_to_vprob(MultiPhase* mphase, VCS_PROB* vprob)
         VolPhase->p_activityConvention = tPhase->activityConvention();
 
         // Assign the value of eqn of state. Handle conflicts here.
-        switch (eos) {
-        case cIdealGas:
+        if (eos == "IdealGas") {
             VolPhase->m_eqnState = VCS_EOS_IDEAL_GAS;
-            break;
-        case cIncompressible:
+        } else if (eos == "ConstDensity") {
             VolPhase->m_eqnState = VCS_EOS_CONSTANT;
-            break;
-        case cSurf:
-            throw CanteraError("VCSnonideal", "cSurf not handled yet.");
-        case cStoichSubstance:
+        } else if (eos == "StoichSubstance") {
             VolPhase->m_eqnState = VCS_EOS_STOICH_SUB;
-            break;
-        case cPureFluid:
-            if (printLvl > 1) {
-                plogf("cPureFluid not recognized yet by VCSnonideal\n");
-            }
-            break;
-        case cEdge:
-            throw CanteraError("VCSnonideal", "cEdge not handled yet.");
-        case cIdealSolidSolnPhase0:
-        case cIdealSolidSolnPhase1:
-        case cIdealSolidSolnPhase2:
+        } else if (eos == "IdealSolidSoln") {
             VolPhase->m_eqnState = VCS_EOS_IDEAL_SOLN;
-            break;
-        default:
+        } else if (eos == "Surf" || eos == "Edge") {
+            throw CanteraError("VCSnonideal",
+                               "Surface/edge phase not handled yet.");
+        } else {
             if (printLvl > 1) {
-                plogf("Unknown Cantera EOS to VCSnonideal: %d\n", eos);
+                writelog("Unknown Cantera EOS to VCSnonideal: '{}'\n", eos);
             }
             VolPhase->m_eqnState = VCS_EOS_UNK_CANTERA;
-            break;
         }
 
         // Transfer all of the element information from the ThermoPhase object
diff --git a/src/equil/vcs_VolPhase.cpp b/src/equil/vcs_VolPhase.cpp
index d6512d4e3..252d5d08c 100644
--- a/src/equil/vcs_VolPhase.cpp
+++ b/src/equil/vcs_VolPhase.cpp
@@ -731,21 +731,13 @@ void vcs_VolPhase::setPtrThermoPhase(ThermoPhase* tp_ptr)
     if (nsp == 1) {
         m_isIdealSoln = true;
     } else {
-        int eos = TP_ptr->eosType();
-        switch (eos) {
-        case cIdealGas:
-        case cIncompressible:
-        case cSurf:
-        case cMetal:
-        case cStoichSubstance:
-        case cSemiconductor:
-        case cLatticeSolid:
-        case cLattice:
-        case cEdge:
-        case cIdealSolidSolnPhase:
+        std::string eos = TP_ptr->type();
+        if (eos == "IdealGas" || eos == "ConstDensity" || eos == "Surf"
+            || eos == "Metal" || eos == "StoichSubstance"
+            || eos == "Semiconductor" || eos == "LatticeSolid"
+            || eos == "Lattice" || eos == "Edge" || eos == "IdealSolidSoln") {
             m_isIdealSoln = true;
-            break;
-        default:
+        } else {
             m_isIdealSoln = false;
         };
     }
diff --git a/src/kinetics/Kinetics.cpp b/src/kinetics/Kinetics.cpp
index 55a8824ae..90fc25bcc 100644
--- a/src/kinetics/Kinetics.cpp
+++ b/src/kinetics/Kinetics.cpp
@@ -132,9 +132,9 @@ void Kinetics::assignShallowPointers(const std::vector<thermo_t*> & tpVector)
             throw CanteraError(" Kinetics::assignShallowPointers",
                                " id() of the ThermoPhase objects isn't the same");
         }
-        if (ntp->eosType() != otp->eosType()) {
+        if (ntp->type() != otp->type()) {
             throw CanteraError(" Kinetics::assignShallowPointers",
-                               " eosType() of the ThermoPhase objects isn't the same");
+                               " type() of the ThermoPhase objects isn't the same");
         }
         if (ntp->nSpecies() != otp->nSpecies()) {
             throw CanteraError(" Kinetics::assignShallowPointers",
@@ -485,13 +485,13 @@ void Kinetics::addPhase(thermo_t& thermo)
     }
 
     // there should only be one surface phase
-    int ptype = -100;
+    string ptype;
     if (type() == cEdgeKinetics) {
-        ptype = cEdge;
+        ptype = "Edge";
     } else if (type() == cInterfaceKinetics) {
-        ptype = cSurf;
+        ptype = "Surf";
     }
-    if (thermo.eosType() == ptype) {
+    if (thermo.type() == ptype) {
         m_surfphase = nPhases();
         m_rxnphase = nPhases();
     }
diff --git a/src/thermo/ConstDensityThermo.cpp b/src/thermo/ConstDensityThermo.cpp
index c7086da9a..6110088e4 100644
--- a/src/thermo/ConstDensityThermo.cpp
+++ b/src/thermo/ConstDensityThermo.cpp
@@ -40,6 +40,8 @@ ThermoPhase* ConstDensityThermo::duplMyselfAsThermoPhase() const
 
 int ConstDensityThermo::eosType() const
 {
+    warn_deprecated("ConstDensityThermo::eosType",
+                    "To be removed after Cantera 2.3.");
     return cIncompressible;
 }
 
diff --git a/src/thermo/DebyeHuckel.cpp b/src/thermo/DebyeHuckel.cpp
index c612b8e0f..ab573a6ee 100644
--- a/src/thermo/DebyeHuckel.cpp
+++ b/src/thermo/DebyeHuckel.cpp
@@ -141,6 +141,8 @@ ThermoPhase* DebyeHuckel::duplMyselfAsThermoPhase() const
 
 int DebyeHuckel::eosType() const
 {
+    warn_deprecated("DebyeHuckel::eosType",
+                    "To be removed after Cantera 2.3.");
     int res;
     switch (m_formGC) {
     case 0:
diff --git a/src/thermo/FixedChemPotSSTP.cpp b/src/thermo/FixedChemPotSSTP.cpp
index 412e4b91f..016dc6ad1 100644
--- a/src/thermo/FixedChemPotSSTP.cpp
+++ b/src/thermo/FixedChemPotSSTP.cpp
@@ -100,6 +100,8 @@ ThermoPhase* FixedChemPotSSTP::duplMyselfAsThermoPhase() const
 
 int FixedChemPotSSTP::eosType() const
 {
+    warn_deprecated("FixedChemPotSSTP::eosType",
+                    "To be removed after Cantera 2.3.");
     return cFixedChemPot;
 }
 
diff --git a/src/thermo/HMWSoln.cpp b/src/thermo/HMWSoln.cpp
index b3b18fefa..4d6bbb237 100644
--- a/src/thermo/HMWSoln.cpp
+++ b/src/thermo/HMWSoln.cpp
@@ -373,6 +373,8 @@ ThermoPhase* HMWSoln::duplMyselfAsThermoPhase() const
 
 int HMWSoln::eosType() const
 {
+    warn_deprecated("HMWSoln::eosType",
+                    "To be removed after Cantera 2.3.");
     int res;
     switch (m_formGC) {
     case 0:
diff --git a/src/thermo/IdealSolidSolnPhase.cpp b/src/thermo/IdealSolidSolnPhase.cpp
index 40a98eda9..c790a7b6d 100644
--- a/src/thermo/IdealSolidSolnPhase.cpp
+++ b/src/thermo/IdealSolidSolnPhase.cpp
@@ -90,6 +90,8 @@ ThermoPhase* IdealSolidSolnPhase::duplMyselfAsThermoPhase() const
 
 int IdealSolidSolnPhase::eosType() const
 {
+    warn_deprecated("EdgePhase::IdealSolidSolnPhase",
+                    "To be removed after Cantera 2.3.");
     integer res;
     switch (m_formGC) {
     case 0:
diff --git a/src/thermo/IdealSolnGasVPSS.cpp b/src/thermo/IdealSolnGasVPSS.cpp
index f85245687..4749ddaa0 100644
--- a/src/thermo/IdealSolnGasVPSS.cpp
+++ b/src/thermo/IdealSolnGasVPSS.cpp
@@ -73,6 +73,8 @@ ThermoPhase* IdealSolnGasVPSS::duplMyselfAsThermoPhase() const
 
 int IdealSolnGasVPSS::eosType() const
 {
+    warn_deprecated("EdgePhase::IdealSolnGasVPSS",
+                    "To be removed after Cantera 2.3.");
     if (m_idealGas) {
         return cIdealSolnGasVPSS;
     }
diff --git a/src/thermo/IonsFromNeutralVPSSTP.cpp b/src/thermo/IonsFromNeutralVPSSTP.cpp
index ff0342293..0d2979eea 100644
--- a/src/thermo/IonsFromNeutralVPSSTP.cpp
+++ b/src/thermo/IonsFromNeutralVPSSTP.cpp
@@ -164,6 +164,8 @@ void IonsFromNeutralVPSSTP::constructPhaseXML(XML_Node& phaseNode, std::string i
 
 int IonsFromNeutralVPSSTP::eosType() const
 {
+    warn_deprecated("IonsFromNeutralVPSSTP::eosType",
+                    "To be removed after Cantera 2.3.");
     return cIonsFromNeutral;
 }
 
diff --git a/src/thermo/MetalSHEelectrons.cpp b/src/thermo/MetalSHEelectrons.cpp
index 2193818cd..79f1ef27a 100644
--- a/src/thermo/MetalSHEelectrons.cpp
+++ b/src/thermo/MetalSHEelectrons.cpp
@@ -59,6 +59,8 @@ ThermoPhase* MetalSHEelectrons::duplMyselfAsThermoPhase() const
 
 int MetalSHEelectrons::eosType() const
 {
+    warn_deprecated("MetalSHEelectrons::eosType",
+                    "To be removed after Cantera 2.3.");
     return cMetalSHEelectrons;
 }
 
diff --git a/src/thermo/MineralEQ3.cpp b/src/thermo/MineralEQ3.cpp
index 156192cef..9fbe9edf5 100644
--- a/src/thermo/MineralEQ3.cpp
+++ b/src/thermo/MineralEQ3.cpp
@@ -68,6 +68,8 @@ ThermoPhase* MineralEQ3::duplMyselfAsThermoPhase() const
 
 int MineralEQ3::eosType() const
 {
+    warn_deprecated("MineralEQ3::eosType",
+                    "To be removed after Cantera 2.3.");
     return cStoichSubstance;
 }
 
diff --git a/src/thermo/PhaseCombo_Interaction.cpp b/src/thermo/PhaseCombo_Interaction.cpp
index 41db6fe52..0e762880c 100644
--- a/src/thermo/PhaseCombo_Interaction.cpp
+++ b/src/thermo/PhaseCombo_Interaction.cpp
@@ -84,6 +84,8 @@ ThermoPhase* PhaseCombo_Interaction::duplMyselfAsThermoPhase() const
 
 int PhaseCombo_Interaction::eosType() const
 {
+    warn_deprecated("PhaseCombo_Interaction::eosType",
+                    "To be removed after Cantera 2.3.");
     return cPhaseCombo_Interaction;
 }
 
diff --git a/src/thermo/RedlichKwongMFTP.cpp b/src/thermo/RedlichKwongMFTP.cpp
index 90307fb7c..ea7a0ed50 100644
--- a/src/thermo/RedlichKwongMFTP.cpp
+++ b/src/thermo/RedlichKwongMFTP.cpp
@@ -112,6 +112,8 @@ ThermoPhase* RedlichKwongMFTP::duplMyselfAsThermoPhase() const
 
 int RedlichKwongMFTP::eosType() const
 {
+    warn_deprecated("RedlichKwongMFTP::eosType",
+                    "To be removed after Cantera 2.3.");
     return cRedlichKwongMFTP;
 }
 
diff --git a/src/thermo/SingleSpeciesTP.cpp b/src/thermo/SingleSpeciesTP.cpp
index d9b1780b6..79b270548 100644
--- a/src/thermo/SingleSpeciesTP.cpp
+++ b/src/thermo/SingleSpeciesTP.cpp
@@ -51,6 +51,8 @@ ThermoPhase* SingleSpeciesTP::duplMyselfAsThermoPhase() const
 
 int SingleSpeciesTP::eosType() const
 {
+    warn_deprecated("SingleSpeciesTP::eosType",
+                    "To be removed after Cantera 2.3.");
     throw NotImplementedError("SingleSpeciesTP::eosType");
 }
 
diff --git a/src/thermo/StoichSubstance.cpp b/src/thermo/StoichSubstance.cpp
index fbef58522..6266591c6 100644
--- a/src/thermo/StoichSubstance.cpp
+++ b/src/thermo/StoichSubstance.cpp
@@ -55,6 +55,8 @@ ThermoPhase* StoichSubstance::duplMyselfAsThermoPhase() const
 
 int StoichSubstance::eosType() const
 {
+    warn_deprecated("StoichSubstance::eosType",
+                    "To be removed after Cantera 2.3.");
     return cStoichSubstance;
 }
 
diff --git a/src/thermo/ThermoFactory.cpp b/src/thermo/ThermoFactory.cpp
index 6b4443646..1b8d7401b 100644
--- a/src/thermo/ThermoFactory.cpp
+++ b/src/thermo/ThermoFactory.cpp
@@ -114,6 +114,7 @@ ThermoPhase* ThermoFactory::newThermoPhase(const std::string& model)
 
 std::string eosTypeString(int ieos, int length)
 {
+    warn_deprecated("eosTypeString", "To be removed after Cantera 2.3.");
     for (int n = 0; n < ntypes; n++) {
         if (_itypes[n] == ieos) {
             return _types[n];
diff --git a/src/thermo/VPSSMgrFactory.cpp b/src/thermo/VPSSMgrFactory.cpp
index c516bb2a9..7ecac5b3c 100644
--- a/src/thermo/VPSSMgrFactory.cpp
+++ b/src/thermo/VPSSMgrFactory.cpp
@@ -265,13 +265,6 @@ VPSSMgr* VPSSMgrFactory::newVPSSMgr(VPStandardStateTP* vp_ptr,
         return create(vpssManager, vp_ptr, spth);
     }
 
-    // Handle special cases based on the VPStandardState types
-    if (vp_ptr->eosType() == cVPSS_IdealGas) {
-        return new VPSSMgr_IdealGas(vp_ptr, spth);
-    } else if (vp_ptr->eosType() == cVPSS_ConstVol) {
-        return new VPSSMgr_ConstVol(vp_ptr, spth);
-    }
-
     int inasaIG = 0, inasaCV = 0, ishomateIG = 0, ishomateCV = 0,
         isimpleIG = 0, isimpleCV = 0, iwater = 0, itpx = 0, iother = 0;
     int ihptx = 0;
diff --git a/src/zeroD/IdealGasConstPressureReactor.cpp b/src/zeroD/IdealGasConstPressureReactor.cpp
index e51f89b4c..c460b4763 100644
--- a/src/zeroD/IdealGasConstPressureReactor.cpp
+++ b/src/zeroD/IdealGasConstPressureReactor.cpp
@@ -14,7 +14,7 @@ void IdealGasConstPressureReactor::setThermoMgr(ThermoPhase& thermo)
 {
     //! @TODO: Add a method to ThermoPhase that indicates whether a given
     //! subclass is compatible with this reactor model
-    if (thermo.eosType() != cIdealGas) {
+    if (thermo.type() != "IdealGas") {
         throw CanteraError("IdealGasReactor::setThermoMgr",
                            "Incompatible phase type provided");
     }
diff --git a/src/zeroD/IdealGasReactor.cpp b/src/zeroD/IdealGasReactor.cpp
index 55b993b0a..1b73f1586 100644
--- a/src/zeroD/IdealGasReactor.cpp
+++ b/src/zeroD/IdealGasReactor.cpp
@@ -13,7 +13,7 @@ void IdealGasReactor::setThermoMgr(ThermoPhase& thermo)
 {
     //! @TODO: Add a method to ThermoPhase that indicates whether a given
     //! subclass is compatible with this reactor model
-    if (thermo.eosType() != cIdealGas) {
+    if (thermo.type() != "IdealGas") {
         throw CanteraError("IdealGasReactor::setThermoMgr",
                            "Incompatible phase type provided");
     }
diff --git a/test_problems/VCSnonideal/LatticeSolid_LiSi/output_blessed.txt b/test_problems/VCSnonideal/LatticeSolid_LiSi/output_blessed.txt
index 7e63bbc02..f284199d5 100644
--- a/test_problems/VCSnonideal/LatticeSolid_LiSi/output_blessed.txt
+++ b/test_problems/VCSnonideal/LatticeSolid_LiSi/output_blessed.txt
@@ -3,9 +3,9 @@ Number of elements = 3
 dg_corr = -1.57754e+08
 um_li_chempot = -1.65555e+08
 Trying VCS equilibrium solver
-Unknown Cantera EOS to VCSnonideal: 0
-Unknown Cantera EOS to VCSnonideal: 20
-Unknown Cantera EOS to VCSnonideal: 70
+Unknown Cantera EOS to VCSnonideal: 'Margules'
+Unknown Cantera EOS to VCSnonideal: 'LatticeSolid'
+Unknown Cantera EOS to VCSnonideal: 'FixedChemPot'
 
 ================================================================================
 ================ Cantera_to_vprob: START OF PROBLEM STATEMENT ====================
diff --git a/test_problems/VCSnonideal/LatticeSolid_LiSi/verbose_blessed.txt b/test_problems/VCSnonideal/LatticeSolid_LiSi/verbose_blessed.txt
index 9e8555beb..547f895ac 100644
--- a/test_problems/VCSnonideal/LatticeSolid_LiSi/verbose_blessed.txt
+++ b/test_problems/VCSnonideal/LatticeSolid_LiSi/verbose_blessed.txt
@@ -3,14 +3,14 @@ Number of elements = 3
 dg_corr = -1.57754e+08
 um_li_chempot = -1.65555e+08
 Trying VCS equilibrium solver
-Unknown Cantera EOS to VCSnonideal: 0
+Unknown Cantera EOS to VCSnonideal: 'Margules'
 vcs_Cantera_convert: Species Type 8 not known 
 vcs_Cantera_convert: Species Type 8 not known 
-Unknown Cantera EOS to VCSnonideal: 20
+Unknown Cantera EOS to VCSnonideal: 'LatticeSolid'
 vcs_Cantera_convert: Species Type 8 not known 
 vcs_Cantera_convert: Species Type 1 not known 
 vcs_Cantera_convert: Species Type 1 not known 
-Unknown Cantera EOS to VCSnonideal: 70
+Unknown Cantera EOS to VCSnonideal: 'FixedChemPot'
 vcs_Cantera_convert: Species Type 1 not known 
 
 ================================================================================
diff --git a/test_problems/VCSnonideal/NaCl_equil/good_out.txt b/test_problems/VCSnonideal/NaCl_equil/good_out.txt
index efb54be23..260da603e 100644
--- a/test_problems/VCSnonideal/NaCl_equil/good_out.txt
+++ b/test_problems/VCSnonideal/NaCl_equil/good_out.txt
@@ -1,5 +1,5 @@
 Trying VCS equilibrium solver
-Unknown Cantera EOS to VCSnonideal: 45012
+Unknown Cantera EOS to VCSnonideal: 'HMWSoln'
 
 ================================================================================
 ================ Cantera_to_vprob: START OF PROBLEM STATEMENT ====================