Settings & wiring
Programmer or thermostat not doing its job
Old wall stats and messy wiring centres are extremely common. Incorrect control signals can leave heating off even when hot water is fine.
I’m Stuart from SKR Plumbing & Heating, a Gas Safe heating engineer based in Orpington. If your taps are hot but the rooms feel like a fridge, you’re not alone – “central heating not working but hot water is” is one of the most common calls I get from homes around Orpington, Bromley and Croydon. I have a full guide on it here: heating not working but hot water is.
Sometimes it’s a simple control setting. Sometimes it’s a diverter valve stuck on hot water, a lazy pump or wiring that’s been disturbed during other work. My job is to work out which it is, explain it in plain English and get the house warm again without any drama.
Most days I’m somewhere between Orpington High Street, Bromley South, BR7 and the A21. If you tell me you’ve got heating not working but hot water is, I know it’s a priority – especially with kids, older relatives or people working from home.
When someone rings saying, “radiators not working but hot water is”, I don’t jump straight to “you need a new boiler”. I go through a few quick checks first – often while you’re stood in front of the boiler in your socks near the airing cupboard.
A surprising number of “emergency” visits turn out to be control settings or pressure issues that can be sorted in minutes. If these checks don’t fix it – or they don’t make sense – that’s when it’s time for a proper heating repair visit.
If you smell gas, see scorch marks, hear banging or get error codes – switch off and call a Gas Safe engineer.
Around Orpington, Bromley and Croydon, I see the same handful of faults week after week. If your central heating is not working but hot water is, it’s usually one of these:
Old wall stats and messy wiring centres are extremely common. Incorrect control signals can leave heating off even when hot water is fine.
Classic combi issue. If the valve fails, the boiler keeps giving hot water but never switches to heating. I repair this daily on Worcester, Baxi, Vaillant and Ideal boilers.
A failing pump means the boiler heats itself, not the house. Boiler cycles on/off rapidly.
Cold tops = air. Cold bottoms = sludge. Both need attention before radiators will heat properly.
Many boilers still give hot water at low pressure but lock out heating. If pressure keeps dropping, there’s a leak.
Common on older Worcester, Vaillant, Baxi and Ideal units. Behaviour can be intermittent and misleading.
For a broader look at heating repairs and upgrades, see my central heating services overview.
My working week covers Orpington, Bromley, BR7, Dartford and SE London. Here are real examples of the exact issue you’re dealing with.
If your issue is slightly different – for example **hot water not working but heating is fine** – see the original guide here: hot water but no heating.
Covering Orpington, Bromley, BR7, SE London, North Kent & nearby areas.
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Hot water is often still safe, but if there are loud noises, gas smells or boiler lockouts, switch off immediately.
Check pressure, thermostats and timers only. Leave internal boiler work to a Gas Safe engineer.
Control issues are cheaper; pumps and diverter valves cost more. I always explain costs clearly before starting.
I’ll advise honestly. If parts are rare or breakdowns are frequent, a new boiler installation may be the smarter long-term option.
If you’ve checked the basics and your radiators still refuse to warm up, it’s time for a proper diagnosis. Homeowners, landlords and contractors welcome.
Working daily across Orpington, Bromley, BR7, SE London and North Kent. If you’re cold right now – mention it so I can try to prioritise you.