Programmer
On Fire
Bournemouth
A Bournemouth flat owner called the fire service after smoke and flames erupted from their cupboard. Firefighters isolated the flat and instructed them to call an electrician. We attended immediately, traced the fault, and safely resolved the hazard.
Evidence & Resolution Gallery
Visual inspection logs of the heat damage, overloaded contact blocks, burnt casings, cooked cable tails, and the completed correctly rated switched spur installation.
The Dangerous Overload Traced
A Bournemouth tenant was alarmed when visible flames and thick smoke started rising from the central heating control cupboard. After quickly calling the fire service, firefighters isolated the entire property's electrical supply. They strictly instructed the customer not to re-energize the flat until a qualified electrician completed a full diagnostic investigation and resolved the root cause of the hazard.
We responded to the emergency callout immediately. Upon removing the central heating programmer from the wall, the severity of the damage became instantly clear. The plastic housing had melted, and the internal contacts were completely carbonized and welded together. Sooey black residue coated the plaster behind the mounting box.
Tracing the wiring revealed a severe, hidden installation error: the heavy-load 3kW immersion water heater had been wired directly through the central heating programmer.
Emergency Rectification
Overloaded Relays Identified
A standard heating programmer's contact relays are rated for 5(2)Amps maximum, designed to handle light boiler control loads. An immersion heater pulls approximately 13 Amps. Operating at more than double its physical limit caused continuous arcing, which welded the contacts and ignited the plastic casing.
Cables Cut Back and Stripped
Swapping the programmer alone would have left cooked, brittle cable tails inside the box, which can flake away and lead to a secondary short circuit. We cut back the heat-damaged conductor tails to sound, flexible copper cores with healthy insulation.
Properly Rated 20A Switched Spur Fitted
We permanently isolated the immersion water heater from the low-power central heating programmer. A dedicated, correctly rated 20-Amp double pole switched fused connection spur was installed to power the immersion heater safely.
Soot Removal and Thermal Checks
The carbonised residue was carefully cleaned out of the back box, and thermal integrity checks were conducted using digital testing instrumentation to confirm no residual heating issues remained.
BS 7671 System Integrity Testing
Before re-energizing the consumer unit, we carried out comprehensive dead testing—including insulation resistance tests at 500V—to confirm the circuit was entirely safe to put back into regular service.
"A central heating programmer looks like the most intuitive place to program hot water timing, but low-current contacts cannot cope with heavy immersion heating. Always ensure high-load appliances have dedicated, correctly rated controls."
Experiencing an
Electrical Fault?
If the fire service or your consumer unit has tripped your supply, do not force it back on. Get an approved registered electrician to safely diagnose the fault.