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Gas Safe registered

Boiler repair in Caerphilly, warm again, fast.

Gas Safe registered serving Caerphilly and the surrounding valleys. I diagnose and fix boiler faults fast, no heating, no hot water, fault codes, and pressure issues.

Call Paul · 029 2169 0437
  • Gas call-out £95, first hour included
  • Price agreed before I start
  • Gas Safe & fully insured
Paul, who runs Cardiff & Caerphilly Plumbers, on site in a hard hat and hi-vis.
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Local knowledge

Boiler faults in Caerphilly: exposure, height and pressure

Caerphilly sits higher and more exposed than Cardiff, and both facts show up in the boiler repairs I attend. The exposure means frozen condensate pipes are a more frequent winter call here than down in the city, the boiler locks out with a fault code, the homeowner assumes the worst, and the actual problem is a 22mm plastic pipe on a north-facing wall with no lagging on it.

Height matters in a different way. Mains water pressure and flow fall off with elevation, and properties on the higher ground around the town can be working with noticeably less than a combi boiler was specified to have. The symptom is not a boiler fault at all: it is poor hot water flow, or a shower that drops to a trickle when another tap opens. Replacing the boiler does not fix it. Measuring the incoming flow rate first tells you whether a combi was ever the right appliance for that property.

On sealed systems I also see a lot of expansion vessel failures, which present as pressure that keeps dropping and needing topping up. People often assume they have a leak somewhere in the house and start looking for damp. A failed vessel or a passing pressure relief valve produces exactly the same symptom without a drop of water appearing indoors, and it is a considerably cheaper repair than chasing a leak that is not there.

Boiler repair in Caerphilly

Boiler Repair in Caerphilly.

Reliable, professional service across Caerphilly and the surrounding valleys. Gas Safe registered, fully insured, and the one who turns up.

No Heating

Rapid diagnosis of failed diverter valves, broken pumps, and faulty PCB boards. I carry common parts to fix most boilers on the first visit.

No Hot Water

Hot water issues caused by thermistors, heat exchangers, or diverter valves. Fast fault-finding and same-day repair where possible.

Fault Codes

I interpret and resolve all common boiler fault codes for Worcester Bosch, Vaillant, Ideal, Baxi, and more.

Low Pressure

Low pressure causing your boiler to lock out? I identify leaks and repressurise the system safely.

Pilot Light Out

Pilot light or ignition faults repaired, Gas Safe registered. Never attempt to relight yourself if you suspect a gas issue.

Honest Pricing

A £95 gas call-out covers the first hour of finding the fault. I give you a fixed price before any repair work begins. No surprises.

Section through a kitchen wall showing why an external condensate pipe freezes and locks the boiler out The boiler sits inside on the kitchen wall. Its condensate pipe passes through the wall and runs down the outside. In freezing weather the water standing in that external run turns to ice and blocks it, and the boiler shuts down on a fault. Lagging the pipe, increasing its diameter or re-routing it inside prevents it. inside outside, north-facing wall boiler condensate pipe ice forms here boiler shuts down on a fault lag it, widen it, or re-route it inside
The most common preventable winter breakdown on Cardiff terraces, where the boiler usually sits in a rear kitchen extension and the condensate has to run outside. Cheap to fix, cheaper still to prevent at an autumn service.
Comparison of a combi boiler and a system boiler with a stored cylinder when the incoming mains flow is limited A combi heats water on demand, so the flow arriving from the mains is split between whichever outlets are open, run a tap while showering and each gets roughly half. A system boiler fills a cylinder slowly at whatever rate the main allows and then delivers stored hot water to both outlets at once. Where incoming flow is the limit a larger combi cannot help, because it cannot deliver water it is not being supplied. Combi, heats on demand incoming main shower tap Open both and each gets roughly half. A larger combi changes nothing, it cannot deliver water it is not being supplied. System boiler + cylinder, stores it same incoming main shower tap Fills slowly at whatever rate the main allows, then serves both outlets properly at once. Usually the better answer higher up a hill.
Mains pressure and flow fall with elevation, so this is the conversation I have most often on the higher ground around Caerphilly and Pontypridd. I measure the incoming flow rate before recommending an appliance rather than after.

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24/7 in Caerphilly

Plumbing emergency in Caerphilly?

The phone is on day and night. I'll talk you through getting the water off before I've even set off, and I aim to be with you inside 90 minutes.

Call 029 2169 0437 Emergency plumber in Caerphilly
  • Gas call-out, first hour included£95
  • First half hour, working hours£80
  • Out of hours & weekends£150
  • What I aim for, door to door90 min

Across the UK, gas engineers charge an average £86 just to call out (Gas Engineer Software, Jul 2026). A call-out with the first hour of work typically runs £95 to £150 (Trade2Base, May 2026).

Questions

Frequently asked questions.

My boiler pressure keeps dropping but I cannot find a leak.

Very often there is not one. A failed expansion vessel or a passing pressure relief valve causes the same symptom, with the water discharging outside through the overflow rather than into the house. Both are straightforward repairs and much cheaper than pulling up floors looking for a leak.

My shower goes cold when someone runs a tap, is the boiler failing?

Usually not. On the higher ground around Caerphilly, mains flow can be below what a combi needs to serve two outlets at once. That is a flow rate problem, not a boiler fault, and replacing the boiler will not solve it. I measure the incoming flow before recommending anything.

Why does my boiler cut out in cold weather?

A frozen condensate pipe. It is more common up here than in Cardiff because of the exposure. It is inexpensive to resolve and usually preventable with proper lagging or a re-route.

Keep looking

Boiler repair across South Wales.

Boiler Repair in CardiffLocal page Boiler Repair in BarryLocal page Boiler Repair in NewportLocal page Boiler Repair in PenarthLocal page Boiler Repair in PontypriddLocal page Plumbers in CaerphillyEverything I do locally All plumbing servicesEverything I do

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Need boiler repair in Caerphilly?

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