4.6 Google reviews
Open 24 hours, 7 days Rates agreed before we start Gas Safe registered
Gas Safe registered
ASAP Boiler Repairs engineers with a branded service van

Twenty years on London boilers

About ASAP Boiler Repair

Gas Safe registered and qualified on unvented cylinders, working north and south of the river. What follows is what we can actually stand behind.

Call 0203 868 6134

Answered 24 hours a day by a technical customer service member.

  • Gas Safe registered engineers
  • An engineer as soon as we can, booked around you
  • Cylinder and unvented systems as well as combis
  • Parts guaranteed for a year, rates agreed before work starts

No heating or hot water right now? Call 0203 868 6134. We will tell you the earliest realistic slot rather than the one you want to hear.

Who we are

A heating firm that has been repairing, servicing and replacing boilers across London for more than twenty years.

Most of our work is unglamorous and most of it is the same handful of faults. A diverter valve that has stuck. A plate heat exchanger furred solid by London water. An expansion vessel that lost its charge two winters ago and has been quietly dropping the pressure ever since. Twenty years means we have seen those thousands of times, on every make sold in this country, and it means we recognise them from a description on the phone more often than not.

We work north and south of the river, in houses, flats, conversions and let properties, for homeowners, landlords and managing agents. The line is answered at any hour by somebody technical rather than by a message service, which matters most at two in the morning when what you actually need is a straight answer about whether anybody is coming tonight.

Three things we will not tell you

Every heating firm in London says the same three things. We would rather say something you can check.

You are probably wondering why an about page would start with what a company refuses to claim. Because the three claims below are the ones everybody makes, none of them can be verified by you before you commit, and dropping them is the clearest signal we can give about how the rest of it works.

What everybody saysWhat we say instead
We are the best in LondonNobody can measure that and every firm claims it. Ask instead what reading a diagnosis came from. A real one produces a number
We will be there within the hourWe do not know where our engineers will be when you ring. You get a realistic slot on the phone, and if it is not soon enough you have lost two minutes rather than an evening
We are the cheapestWe are not competing on that. A rate agreed before anybody sets off is worth more than a low figure that grows once the casing is off

The old version of this page said all three. It also described the phone line as a call centre, which it is not. We would rather correct that in public than leave it standing.

ASAP Boiler Repairs engineer explaining a boiler diagnosis to a homeowner

Two qualifications, not one

The combination is less common than it sounds, and it is the reason people stop paying twice.

Gas Safe registration covers gas appliances. It is a legal requirement and every competent heating firm holds it. It does not cover a hot water cylinder.

An unvented cylinder is a pressure vessel, so working on one is notifiable under Approved Document G3 of the Building Regulations and needs a separate qualification, renewed on a five year cycle. Plenty of heating firms hold Gas Safe and stop at the appliance. Plenty of plumbers hold G3 and will not touch the boiler.

Our engineers hold both. In a house with a cylinder, that is the difference between one visit and two, because when the hot water goes the fault is as likely to be in the tank as in the boiler and somebody has to be allowed to look at both.

Did you know

The most common wrong call-out in London goes like this. The hot water stops, the boiler is blamed, a part is fitted to an appliance that was working perfectly, and the problem comes back. In a house with a stored cylinder there are six things that can fail and only one of them is the boiler. Which of the two has stopped, heating or hot water, narrows it further than any fault code does, and it costs nothing to say on the phone.

How a job actually runs

Four commitments, all of them checkable on the day rather than in a strapline.

  • The rate is agreed before anybody sets off. Not after the engineer is standing in your kitchen, and not once the casing is already off.
  • The diagnosis is written down before any repair begins. What has failed, what the parts and labour come to, whether the part is on the van or has to be ordered, and roughly how long it will take. Nothing proceeds until you have seen it.
  • Parts we fit are guaranteed for a year.
  • If a repair is not worth doing, we say so, and there is nothing to pay for being told. Age does not decide that. The failed part does.

What drives the figure on any given job is the part rather than the postcode or the hour of the day, and our guide to repair costs sets out what moves it. The diagnostic method itself, and the instruments a real one uses, is on the gas boiler repair page.

Google Reviews
  • "He was very professional tidy and polite. Would recommend!"

    Anna M.

  • "Very happy with this company very and professionally service. Fixed my leaking TRV and after draining my system and the refilled and vented the air . Thank you I have heating now"

    Jamie K.

  • "Very polite and respectable engineer...had two other heating company that struggle to find the issue with my boiler but ASAP repaired it on the same day thanks absolute life saver"

    JA Morris

Where we work

London, north and south of the river. Every borough, with no distance conditions attached.

We do not qualify coverage by distance, add a surcharge for one postcode over another, or treat the far side of the river as somebody else's problem. What changes between one call and the next is availability, never the rate.

The two halves are set out on boiler repair in north London and boiler repair in south London, and every district we have written up is listed on areas we cover.

Common questions

How long have you been going?

More than twenty years, working across London the whole time. In practice what that buys you is pattern recognition rather than a number on a page: most domestic boiler faults are a short list repeated thousands of times, and having seen them that often means we usually recognise one from a description on the phone before anybody sets off.

Are you available at night and at weekends?

The line is answered 24 hours a day by a technical member of the team, not a message service that takes a number and passes it on in the morning. That is the part that matters at two in the morning, because you get a real answer about whether somebody is coming tonight. What changes out of hours is parts, since merchants are shut, so an overnight visit is often about making the property safe and warm with the permanent repair to follow. See emergency boiler repair.

Do you work on hot water cylinders as well as boilers?

Yes, and it is a large part of what we do. Unvented cylinders are notifiable work needing a G3 qualification on top of Gas Safe registration, and most firms hold one or the other. Ours hold both, so on a house with stored hot water the boiler and the cylinder are diagnosed in one visit rather than two trades and two charges. Our unvented cylinder repair page covers what fails and in what order.

Do you work for landlords and managing agents?

Yes, on the same terms as anybody else, and we report in writing so there is a record of what was found and when. Certificates and repairs can go on the same visit where the appliance passes, which keeps a let property off the market once rather than twice. We cannot take instructions from a tenant on a landlord's behalf, and any firm that says otherwise is setting up an argument about who pays.

What stops a boiler needing you in the first place?

An annual service, honestly. Nearly every breakdown we attend in January was visible in October: a condensate trap silting up, an expansion vessel that has lost its charge, a pipe run that will freeze on the first cold night. All of them are cheap in autumn and an out of hours call in winter. London water is hard enough to fur a heat exchanger faster than most manuals assume, which is the other half of the argument for a yearly service.

Talk to somebody technical

Tell us what has stopped and whether there is a hot water cylinder in an airing cupboard. With those two answers we can usually name the likely part, give you the rate, and book somebody in, all on the one call.

Gas Safe registered. Unvented cylinder qualified. Parts guaranteed for a year. Covering London, north and south of the river, 24 hours a day.

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