Error E32

Safety precautions:

- If you smell gas, evacuate and call the gas emergency number immediately. Do not attempt any checks.

- Isolate electrical supply to the boiler at the fused spur or mains before opening the case. Confirm power is off.

- If you are not competent with basic electrical isolation and testing, stop and call a Gas Safe engineer. Working inside a boiler can be dangerous and may invalidate warranties.

Initial checks a homeowner can do (no internal access required):

1) Try a simple reset: use the boiler reset button or switch off at the mains for 30–60 seconds and restart. Note whether E32 returns immediately or intermittently.

2) Check for visible leaks around the boiler, pipework, condensate trap or base of the unit. Water ingress is a common cause of sensor shorting.

3) Check the boiler pressure gauge is within normal range (typically 1–1.5 bar cold for many systems). Very low or very high pressure can cause other faults but is not the primary cause of E32.

4) Look for obvious signs of corrosion, damp or loose wiring on any external connectors you can safely see without removing the cover.

If you are comfortable and competent with basic electrical work, additional diagnostic steps (isolate power first):

1) Isolate the boiler from the electricity supply. Confirm no power to the unit.

2) Remove the outer case/front panel following the manufacturer instructions. Keep screws and panels safe.

3) Locate the return thermistor: it is usually clipped to the return pipe and has a small 2‑pin or multi-pin push-on connector to the control wiring.

4) Visually inspect the sensor, clip, connector and wires for damage, melted insulation, corrosion or signs of water. Dry any moisture and identify any obvious wiring damage.

5) Carefully unplug the thermistor connector from the wiring loom (take a photo first so you can re-fit correctly).

6) Use a handheld multimeter set to resistance (ohms). With the thermistor disconnected from the boiler harness:

- Measure resistance across the thermistor terminals. A shorted thermistor will show a very low resistance (near zero). An open thermistor will read infinite/OL. A healthy thermistor will show a finite resistance that changes if you warm/cool the sensor (you do not need exact values to detect a clear short or open).

- Also check for short to earth/ground or chassis: measure between each thermistor wire and the boiler metal chassis or ground; any near-zero reading indicates a short to earth.

7) If the thermistor reads as shorted or shorted to earth, the sensor is faulty and should be replaced. If the thermistor reads open/faulty, replace it.

8) If the thermistor resistance looks reasonable but the boiler still reports E32, unplug the thermistor and measure continuity along the wiring harness from the plug to the control board connector (if accessible) to check for wiring short or damage. Repair any damaged wiring; ensure connectors are dry and secure.

9) After replacing or re-seating the sensor and connectors, smear a thin film of heat-sink compound between the thermistor and the pipe per the service manual, reclip the sensor tightly to the pipe, reassemble the casing, reconnect power and test the boiler. Clear the fault via the reset and observe whether E32 reappears.

When to call a professional:

- If you are not comfortable isolating power, opening the boiler case or using a meter.

- If the fault persists after replacing the thermistor or repairing obvious wiring damage.

- If you find water ingress or internal corrosion inside the boiler.

- If other error codes appear or the boiler repeatedly locks out.

A Gas Safe registered engineer should carry out component replacements, wiring repairs inside the appliance and any work that requires removing the boiler from service or accessing gas-related parts. They will also properly test, seal and recommission the boiler. Do not attempt gas or complex electrical repairs yourself.