diff --git a/firmware/Makefile b/firmware/Makefile
index 6f8675f..c3821f9 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -127,6 +127,7 @@ CPPSRC = $(ALLCPPSRC) \
           pwm.cpp \
           pump_dac.cpp \
           sampling.cpp \
+          heater_control.cpp \
           main.cpp
 
 # List ASM source files here.
diff --git a/firmware/heater_control.cpp b/firmware/heater_control.cpp
new file mode 100644
index 0000000..125f0e2
--- /dev/null
+++ b/firmware/heater_control.cpp
@@ -0,0 +1,15 @@
+#include "heater_control.h"
+
+#include "hal.h"
+#include "pwm.h"
+#include "sampling.h"
+
+// 400khz / 1024 = 390hz PWM
+// TODO: this is wired to an inverted output, what do?
+Pwm heaterPwm(PWMD1, 0, 400'000, 1024);
+
+void StartHeaterControl()
+{
+    heaterPwm.Start();
+    heaterPwm.SetDuty(0);
+}
diff --git a/firmware/heater_control.h b/firmware/heater_control.h
new file mode 100644
index 0000000..2bfdca7
--- /dev/null
+++ b/firmware/heater_control.h
@@ -0,0 +1,3 @@
+#pragma once
+
+void StartHeaterControl();
diff --git a/firmware/main.cpp b/firmware/main.cpp
index f4b9c72..866bff1 100644
--- a/firmware/main.cpp
+++ b/firmware/main.cpp
@@ -3,14 +3,10 @@
 #include "chprintf.h"
 
 #include "can.h"
-#include "pwm.h"
+#include "heater_control.h"
 #include "pump_dac.h"
 #include "sampling.h"
 
-// 400khz / 1024 = 390hz PWM
-// TODO: this is wired to an inverted output, what do?
-Pwm heaterPwm(PWMD1, 0, 400'000, 1024);
-
 static const UARTConfig uartCfg =
 {
     .txend1_cb = nullptr,
@@ -44,10 +40,7 @@ int main() {
 
     uartStart(&UARTD1, &uartCfg);
 
-    heaterPwm.Start();
-
-    heaterPwm.SetDuty(0.2f);
-
+    StartHeaterControl();
 
     /*for (int i = 0; i < 500; i++) {
         SetPumpCurrentTarget(current);