Error D.60

Safety precautions:

1) If you smell gas, evacuate the property, ventilate if safe, do not operate electrical switches, and call the emergency gas number immediately. 2) If the boiler or pipes are very hot, avoid touching them and allow them to cool. 3) Do not remove the boiler casing or interfere with internal components. Only a qualified Gas Safe engineer should isolate gas or open the appliance. 4) Do not bypass safety cut‑outs or reset repeatedly if the fault returns.

Initial homeowner checks (safe, basic checks you can do):

1) Record the error: note the exact code (D.60), take a photo of the display and note when it happened and what the boiler was doing. 2) Turn the boiler off at the programmer/controls and the electrical isolator, wait 20–30 minutes to allow the boiler to cool, then switch back on and attempt a single reset using the boiler reset button or control panel. If the fault does not reappear the issue may have been transient — monitor closely. 3) Check the system pressure on the pressure gauge. For many systems pressure should be roughly 1.0–1.5 bar when cold. If pressure is very low (close to 0) top up the system only if you are confident using the filling loop and your boiler manual; otherwise leave and call an engineer. 4) Check radiators: feel inlet/outlet pipes and radiator top/bottom. Very cold radiators while the boiler runs can indicate poor circulation or airlocks. Bleed radiators to remove trapped air and then re‑check pressure. 5) Listen at the boiler for the pump running (a faint vibration or hum). If the pump appears dead or very noisy this can cause overheating. 6) Look for obvious leaks around pipework and the boiler that could cause low water level or pressure loss.

If the fault returns or initial checks do not fix it (professional diagnostics and likely repairs required):

1) Do not continue to regularly reset the boiler. Repeated trips indicate an unresolved safety issue. 2) Call a qualified Gas Safe registered engineer and provide them the fault code, how many times it has occurred, and the observations from your checks. 3) The engineer will isolate and safely open the boiler and carry out systematic checks: read the fault log from the PCB, measure flow and return temperatures under load, check NTC thermistor resistances for flow and return sensors, test continuity and function of the safety temperature limiter (STB), verify correct wiring and connectors, and inspect the pump operation and impeller. 4) The engineer will check for circulation faults (blocked heat exchanger, scale, sludge or debris in the system, seized pump, closed valves or a stuck diverter valve) and may perform a powerflush or partial flush if flow is restricted. 5) They will test the expansion vessel and pressure sensor, inspect the flue and fan for obstruction or excessive flue gas temperatures, and test the PCB and ignition/gas valve circuits if needed. 6) Faulty components identified (temperature sensors, STB/flue limiter, pump, diverter valve, wiring or PCB) should be replaced only by the engineer. 7) After repairs the engineer will recommission the boiler, check for correct temperatures and pressures, clear the fault log, and run the system to confirm the problem is resolved.

Final notes:

- Because D.60 indicates safety cut‑outs due to overtemperature, it should be treated seriously. If the fault repeats or you cannot identify a clear, safe cause from the basic checks, arrange an engineer visit. - Keep records and photos of the fault and any steps you took — this helps the engineer diagnose the underlying cause. - Never bypass safety devices or attempt internal repairs unless you are a qualified Gas Safe engineer.