Boiler
E32
The E32 error code on a Worcester Bosch boiler indicates a fault with the flow temperature sensor (NTC sensor), which prevents the boiler from operating safely. It’s a moderately serious fault — your boiler will likely lock out and stop producing heat or hot water until it’s resolved.
What does this error mean?
Worcester Bosch boilers use a flow NTC (Negative Temperature Coefficient) sensor to monitor the temperature of water leaving the heat exchanger. When the boiler detects an implausible or missing signal from this sensor, it triggers the E32 code and shuts down as a safety precaution. Essentially, the boiler can’t confirm the water is at a safe temperature, so it refuses to fire.
Est. repair cost
£150–£250 for NTC sensor replacement by a Gas Safe engineer (parts + labour)
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 — Reset the boiler: Press and hold the reset button (or follow your model’s reset procedure in the manual) for 3–5 seconds. Some intermittent sensor faults clear on their own after a reset. If the boiler fires up and runs normally, monitor it closely over the next 24 hours.
Step 2 — Check your system pressure: Look at the pressure gauge on the boiler front panel. It should read between 1–1.5 bar when cold. Low pressure can cause circulation issues and false sensor faults. If it’s below 1 bar, top up via the filling loop (consult your boiler manual for instructions).
Step 3 — Bleed your radiators: Trapped air in the system can cause localised hot spots that confuse the flow sensor. Bleed all radiators starting from the ground floor, then re-check and top up boiler pressure if needed.
Step 4 — Check for visible error persistence: If E32 returns immediately after a reset, or the boiler locks out again within a short period, do not attempt further DIY. This is now a job for a Gas Safe registered engineer.
Step 5 — Do NOT attempt to replace the NTC sensor or inspect internal wiring yourself. Working inside a gas boiler without Gas Safe registration is illegal and dangerous. Call a qualified engineer for all internal component work.
📞 When to call a professional
Call a Gas Safe registered engineer if the E32 code returns after a reset, if your boiler won’t reset at all, or if you have no heating or hot water. When you call, tell them your boiler model (found on the front panel), that you’re seeing error code E32, and that you suspect a flow NTC sensor fault — this helps them arrive with the right parts. Do not attempt to open the boiler casing yourself.
⚖️ Repair or replace?
An NTC sensor replacement by a Gas Safe engineer typically costs £150–£250 including parts and labour, making it a straightforward and worthwhile repair on most boilers. If your Worcester Bosch boiler is over 10–12 years old and this fault is accompanied by other recurring issues, it may be more economical to replace the unit — a new Worcester Bosch boiler costs £1,800–£2,800 installed. For a boiler under 8 years old in otherwise good condition, always repair first.