No heating and no hot water: the checks to make before you call

What matters most with a total loss of heating and hot water

• Check the fused spur and any nearby tripped RCD first
• Confirm the programmer or thermostat clock is correct and calling for heat
• Read the pressure gauge; below the minimum stops both heating and hot water
• A frozen condensate pipe can silently take out both functions in cold snaps
• If all four check out, the fault is inside the boiler and needs an engineer

A total loss of heating and hot water explained in plain terms

Start with power: check the boiler's fused spur switch, the mains socket, and whether a nearby RCD has tripped and taken the boiler circuit with it. Next check the programmer or smart thermostat is calling for heat and that its clock and battery have not reset after a power cut, since a stopped clock will happily leave the boiler waiting for a time that never comes. Then look at the pressure gauge, because a sealed system that has dropped below its minimum will lock the boiler out of both heating and hot water together. Only after these three are ruled out does the fault sit inside the appliance, which is where a Gas Safe registered engineer for a gas boiler, or an OFTEC-registered technician for an oil boiler, needs to take over.

Where we deal with this

• Gurney Slade (BA3) · 6 mi
• Coxley (BA5) · 11 mi
• Whatley (BA11) · 8 mi

How this plays out across our coverage area

Across BA3 to BA5 and the villages around the Mendips we get more total-loss calls in the first proper cold snap of the year than any other week, usually from a mix of frozen condensate runs and boilers that simply have not run their hot water function since spring. Both are quick checks on a visit, and neither needs a new boiler.

Questions we get asked

Should I try resetting the boiler straight away?

Check power, timer and pressure first. Resetting before ruling those out just repeats the same failed attempt.

Could a power cut really cause this?

Yes. Many programmers and smart controls revert to a default schedule or lose the correct time after a power interruption, and some default schedules do not call for heat at all.

Is a frozen condensate pipe something I can thaw myself?

You can gently warm an accessible external pipe with a warm (not boiling) cloth or hot water bottle. Do not use boiling water or an open flame, and stop if you are unsure which pipe it is.