diff --git a/include/cantera/zeroD/PID_Controller.h b/include/cantera/zeroD/PID_Controller.h
deleted file mode 100644
index 189b25e0c..000000000
--- a/include/cantera/zeroD/PID_Controller.h
+++ /dev/null
@@ -1,157 +0,0 @@
-/**
- *  @file PID_Controller.h
- */
-
-// Copyright 2001  California Institute of Technology
-
-#ifndef CT_PID_H
-#define CT_PID_H
-
-namespace Cantera
-{
-
-class PID_Controller
-{
-
-public:
-
-    /// Default constructor.
-    PID_Controller() : m_v0(Undef), m_p(Undef), m_i(Undef), m_d(Undef),
-        m_setpoint(Undef), m_last(Undef), m_time(Undef),
-        m_xint(Undef), m_out(Undef), m_dt(Undef) {}
-
-    /**
-     * Copy constructor. Gains and setpoint are copied, but not
-     * the internal parameters defining the state of the
-     * controller.  Method 'reset' must be called for the copy
-     * before using it.
-     */
-    PID_Controller(const PID_Controller& pid)
-        : m_v0(pid.m_v0), m_p(pid.m_p), m_i(pid.m_i), m_d(pid.m_d),
-          m_setpoint(pid.m_setpoint),
-          m_last(Undef), m_time(Undef), m_xint(Undef) {}
-
-    /**
-     * Assignment operator. @see Copy constructor.
-     */
-    PID_Controller& operator=(const PID_Controller& pid) {
-        if (this == &pid) {
-            return *this;
-        }
-        m_v0 = pid.m_v0;
-        m_p = pid.m_p;
-        m_i = pid.m_i;
-        m_d = pid.m_d;
-        m_setpoint = pid.m_setpoint;
-        m_last = Undef;
-        m_time = Undef;
-        m_xint = Undef;
-        return *this;
-    }
-
-    /**
-     * Reset the start time to time, and the current value of
-     * the input to input. Sets the integrated error signal to zero.
-     */
-    void reset(doublereal time = 0.0, doublereal input = 0.0) {
-        m_time = time;
-        m_last = input;
-        m_xint = 0.0;
-        m_out = m_v0;
-        m_dt = 1.0;
-        m_maxerr = 0.0;
-    }
-
-    doublereal setpoint(doublereal y = Undef) {
-        if (y != Undef) {
-            m_setpoint = y;
-        }
-        return m_setpoint;
-    }
-
-    bool getGains(vector_fp& gains) {
-        gains.resize(4);
-        return getGains(4, gains.begin());
-    }
-
-    bool getGains(int n, doublereal* gains) {
-        if (n < 4) {
-            return false;
-        }
-        gains[0] = m_v0;
-        gains[1] = m_p;
-        gains[2] = m_i;
-        gains[3] = m_d;
-        return true;
-    }
-
-    bool setGains(const vector_fp& gains) {
-        return setGains(int(gains.size()), gains.begin());
-    }
-
-    bool setGains(int n, const doublereal* gains) {
-        if (n < 4) {
-            return false;
-        }
-        m_v0 = gains[0];
-        m_p = gains[1];
-        m_i = gains[2];
-        m_d = gains[3];
-        if (m_p < 0.0 || m_i < 0.0 || m_d < 0.0) {
-            return false;
-        }
-        return true;
-    }
-
-    void update(doublereal time, doublereal input) {
-        if (time <= m_time) {
-            return;
-        }
-        doublereal err = input - m_setpoint;
-        if (fabs(err) > m_maxerr) {
-            m_maxerr = fabs(err);
-        }
-        m_dt = time - m_time;
-        m_xint += (0.5*(input + m_last) - m_setpoint) * m_dt;
-        m_last = input;
-        m_time = time;
-        doublereal xdot = (input - m_last)/m_dt;
-        m_out = m_v0 - m_p*(input - m_setpoint) - m_i*m_xint
-                - m_d*xdot;
-    }
-
-    doublereal output(doublereal input) {
-        return fmaxx(0.0,
-                     m_out - (m_p + m_d/m_dt + 0.5*m_i*m_dt)*(input - m_last));
-    }
-
-    doublereal maxError() {
-        return m_maxerr;
-    }
-
-    bool ready() {
-        return (m_time != Undef
-                && m_setpoint != Undef
-                && m_v0 != Undef);
-    }
-
-protected:
-
-    doublereal
-    m_v0,
-    m_p,
-    m_i,
-    m_d,
-    m_setpoint,
-    m_maxerr,
-    m_last,
-    m_time,
-    m_xint,
-    m_out,
-    m_dt;
-};
-
-}
-
-#endif
-
diff --git a/src/zeroD/Makefile.am b/src/zeroD/Makefile.am
index 719acb5d1..0281fd701 100644
--- a/src/zeroD/Makefile.am
+++ b/src/zeroD/Makefile.am
@@ -4,7 +4,6 @@ h_sources  = $(top_builddir)/include/cantera/zeroD/Reactor.h \
              $(top_builddir)/include/cantera/zeroD/Wall.h \
              $(top_builddir)/include/cantera/zeroD/ReactorNet.h \
              $(top_builddir)/include/cantera/zeroD/flowControllers.h \
-             $(top_builddir)/include/cantera/zeroD/PID_Controller.h \
              $(top_builddir)/include/cantera/zeroD/Reservoir.h \
              $(top_builddir)/include/cantera/zeroD/FlowReactor.h \
              $(top_builddir)/include/cantera/zeroD/ConstPressureReactor.h \