diff --git a/firmware/boards/f0_module/wideband_board_config.h b/firmware/boards/f0_module/wideband_board_config.h
index 529dcf9..b71fc98 100644
--- a/firmware/boards/f0_module/wideband_board_config.h
+++ b/firmware/boards/f0_module/wideband_board_config.h
@@ -17,3 +17,9 @@
 //    Nernst voltage & ESR sense
 // *******************************
 #define VM_RESISTOR_VALUE (10)
+
+// *******************************
+// Hack: allow pump driving above target temperature
+// minus this offset to avoid Vnerns voltage clamp near 0V
+// *******************************
+#define START_PUMP_TEMP_OFFSET	(200.0)
diff --git a/firmware/heater_control.cpp b/firmware/heater_control.cpp
index 03329ec..44ba203 100644
--- a/firmware/heater_control.cpp
+++ b/firmware/heater_control.cpp
@@ -27,6 +27,11 @@ bool HeaterControllerBase::IsRunningClosedLoop() const
     return heaterState == HeaterState::ClosedLoop;
 }
 
+float HeaterControllerBase::GetTargetTemp() const
+{
+    return m_targetTempC;
+}
+
 float HeaterControllerBase::GetHeaterEffectiveVoltage() const
 {
     return heaterVoltage;
diff --git a/firmware/heater_control.h b/firmware/heater_control.h
index df0b2a2..02149a2 100644
--- a/firmware/heater_control.h
+++ b/firmware/heater_control.h
@@ -25,6 +25,7 @@ struct IHeaterController
     virtual bool IsRunningClosedLoop() const = 0;
     virtual float GetHeaterEffectiveVoltage() const = 0;
     virtual HeaterState GetHeaterState() const = 0;
+    virtual float GetTargetTemp() const = 0;
 };
 
 class HeaterControllerBase : public IHeaterController
@@ -37,6 +38,7 @@ public:
     bool IsRunningClosedLoop() const override;
     float GetHeaterEffectiveVoltage() const override;
     HeaterState GetHeaterState() const override;
+    float GetTargetTemp() const override;
 
     virtual void SetDuty(float duty) const = 0;
 
diff --git a/firmware/pump_control.cpp b/firmware/pump_control.cpp
index 601d7d9..9bf6eb9 100644
--- a/firmware/pump_control.cpp
+++ b/firmware/pump_control.cpp
@@ -38,7 +38,11 @@ static void PumpThread(void*)
             const auto& heater = GetHeaterController(ch);
 
             // Only actuate pump when running closed loop!
-            if (heater.IsRunningClosedLoop())
+            if (heater.IsRunningClosedLoop() ||
+#ifdef START_PUMP_TEMP_OFFSET
+                (sampler.GetSensorTemperature() >= heater.GetTargetTemp() - START_PUMP_TEMP_OFFSET) ||
+#endif
+                (0))
             {
                 float nernstVoltage = sampler.GetNernstDc();
 
diff --git a/firmware/pump_dac.cpp b/firmware/pump_dac.cpp
index ed543a6..9d6576f 100644
--- a/firmware/pump_dac.cpp
+++ b/firmware/pump_dac.cpp
@@ -90,11 +90,13 @@ void InitPumpDac()
 
 void SetPumpCurrentTarget(int ch, int32_t microampere)
 {
+#ifndef START_PUMP_TEMP_OFFSET
     // Don't allow pump current when the sensor isn't hot
     if (!GetHeaterController(ch).IsRunningClosedLoop())
     {
         microampere = 0;
     }
+#endif
 
     state[ch].curIpump = microampere;