My boiler has a fault code. What does it mean?

Codes are manufacturer specific, so the same number means different things on different boilers, but the families are consistent: ignition lockout, low water pressure, overheat, fan or flue fault, and sensor failure. Give us the make, the model and the code when you enquire and it usually identifies the part before anyone comes out.

Why does my boiler keep losing pressure?

Water is leaving the system somewhere. Either a small leak on pipework, a radiator valve or the boiler itself, a failed expansion vessel that can no longer absorb expansion so the pressure relief discharges, or an automatic air vent passing. The three are distinguishable on the day, and topping up repeatedly without finding out which is treating a symptom.

Can a frozen condensate pipe be fixed myself?

Usually, and it is worth trying. Find the plastic pipe running out through the wall, pour warm, not boiling, water along its external length, and reset the boiler. If it comes back on, that was it. If it freezes every winter the pipe needs rerouting or upsizing, because the thaw is a fix for today rather than for next year.

When is a repair not worth doing?

When the parts are no longer reliably available, when the repair cost is a meaningful share of a replacement on a boiler already well into its life, or when there are several faults at once rather than one. We give you the part cost and the replacement cost side by side and let you decide, rather than deciding it for you.

Will you have the part on the van?

For the common failures, often. Diverter cartridges, pressure sensors, automatic air vents, pumps and expansion vessels for the usual models are stocked. Anything manufacturer specific is ordered against the model number, which is why the make, model and fault code in the first message genuinely shortens the job.

Boiler Repair
In London

A boiler that has stopped is usually telling you what is wrong, either with a code on the display or with the pattern of what still works.

Fault code read before anything else
Repair or replace, stated plainly
Parts priced before they are fitted

Quick Quote Online Call 07401 062636

Excellent5.07 reviews

Reviews

What Customers Say About The Work

Excellent5.07 reviews

Really pleased with the service from Drain Plumb Contractors. The work was carried out professionally, everything was explained clearly, and the area was left clean and tidy afterwards. Would happily recommend them to anyone looking for a reliable plumber.
Google reviewer
Had an urgent plumbing problem and needed someone to help. Drain Plumb Contractors were professional and helpful throughout, and the issue was dealt with efficiently. A stressful situation made much easier. Thank you for the great service.
Google reviewer
Great service for a drainage problem that needed sorting. The team were helpful, explained what needed doing and handled the job professionally. Everything was left in good order afterwards. I'd definitely consider using Drain Plumb Contractors again.
Google reviewer
Really good experience from start to finish. Friendly, professional and easy to deal with, with clear communication throughout. It's reassuring to find tradespeople who take the time to explain the work and treat your property with care. Would recommend.
Google reviewer
Very happy with the service provided. Communication was clear, the work was explained before getting started, and the whole process was straightforward. Good workmanship and a professional approach. I'd be happy to use Drain Plumb Contractors for future work.
Google reviewer
Very pleased with the plumbing work. The job was completed to a good standard, and the attention to detail was appreciated. Everything was left neat and tidy, and the service was professional throughout. Would happily recommend them.
Google reviewer
I've been very happy with the service from Drain Plumb Contractors. They're professional, approachable and take the time to explain things properly. It's good to have a company you can contact when plumbing or drainage work is needed. Would recommend them to others.
Google reviewer

Start With The Code
The fault code and the pressure gauge narrow the cause before anyone visits.
Repair Economics
If the repair costs more than the boiler is worth, you are told so.
Parts In Writing
What failed, what replaces it and what it costs, before it goes in.
No Charge To Ask
Describing the fault costs nothing and commits you to nothing.

A boiler condensate pipe running out through an exterior wall into a gully on a frosty morning

Boiler Repair

The two checks before you call

System pressure, read off the gauge on the front or underneath. Cold, it should sit around one bar. Near zero and the boiler will lock out and refuse to fire, and the reason is a leak somewhere, a failed expansion vessel or an automatic air vent passing. Topping it up gets the heating back on and tells us something useful: if it drops again within days, we are looking for water going somewhere.

The condensate pipe, if any part of it runs outside. A frozen condensate is the commonest winter lockout there is, and thawing the external length with warm water restores it in minutes. If it freezes every year, the pipe is undersized or badly routed and that is a permanent fix rather than an annual ritual.

Boiler Repair is priced after the job has been seen, anywhere in the areas we cover. Send the postcode and a few lines about what it is doing when you contact us, and the answer comes back in writing.

Quick Quote Online

The Job In Detail

What Boiler Repair Involves

What the symptoms usually mean

Heating but no hot water, or hot water but no heating, points at the diverter valve, which is the component that decides where the heat goes. Firing then cutting out within a minute or two is short cycling, normally from poor circulation, a blocked filter or a pump problem rather than from the burner. Ignition lockout, where it tries three times and gives up, is typically the electrode, the gas valve or the flue. Pressure that climbs when the heating runs and will not come down is usually a failed expansion vessel or a passing filling loop. And banging on ignition is often a partially blocked burner.

Parts, age and the honest answer

Any boiler can be repaired. Not every boiler should be. Once a model is past its spares availability, individual parts cost more than they did and some stop existing, and a repair bill that approaches a meaningful share of replacement is money spent on a machine that will be back. We tell you which situation yours is in, with the part price and the alternative, and we do not quote a replacement for something that needs a thirty pound diverter cartridge.

What to tell us when you get in touch

The make and model from the sticker inside the door, the fault code on the display, the system pressure, and which of heating and hot water still works. Those four answers often identify the part before anyone sets off, which means it arrives on the first visit.

Quick Quote Online

How It Works

How A Boiler Repair Job Runs

Send the fault code

The code on the display, the make and model, and what the boiler is doing.

Diagnosis

The code and the symptoms are read together to find the part at fault.

Repair priced

The part and the labour in writing, with an honest word if replacing makes more sense.

Boiler showing a code? Send it to us with the make and model.

Get My Boiler Fixed

FAQs

Boiler Repair Questions

Codes are manufacturer specific, so the same number means different things on different boilers, but the families are consistent: ignition lockout, low water pressure, overheat, fan or flue fault, and sensor failure. Give us the make, the model and the code when you enquire and it usually identifies the part before anyone comes out.
Water is leaving the system somewhere. Either a small leak on pipework, a radiator valve or the boiler itself, a failed expansion vessel that can no longer absorb expansion so the pressure relief discharges, or an automatic air vent passing. The three are distinguishable on the day, and topping up repeatedly without finding out which is treating a symptom.
Usually, and it is worth trying. Find the plastic pipe running out through the wall, pour warm, not boiling, water along its external length, and reset the boiler. If it comes back on, that was it. If it freezes every winter the pipe needs rerouting or upsizing, because the thaw is a fix for today rather than for next year.
When the parts are no longer reliably available, when the repair cost is a meaningful share of a replacement on a boiler already well into its life, or when there are several faults at once rather than one. We give you the part cost and the replacement cost side by side and let you decide, rather than deciding it for you.
For the common failures, often. Diverter cartridges, pressure sensors, automatic air vents, pumps and expansion vessels for the usual models are stocked. Anything manufacturer specific is ordered against the model number, which is why the make, model and fault code in the first message genuinely shortens the job.

Resources

Boiler Repair Questions, Answered

A combi boiler with a fault code on its display and the pressure gauge reading low

Boiler Repair

What A Boiler Fault Code Actually Tells You

Everything we have written on this job, newest first, is in the boiler repair resources.

Boiler Repair

What Is The
Boiler Doing?

The fault code, the make and model, the pressure on the gauge and when it started. That is usually enough to know what we are looking for.

Excellent5.07 reviews

07401 062636

info@drainplumbcontractors.co.uk

Greater London

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Boiler Repair
In London

Reviews

What Customers Say About The Work

Start With The Code

Repair Economics

Parts In Writing

No Charge To Ask

Boiler Repair

The two checks before you call

The Job In Detail