Gas Safe registered
SW3 SW7 SW10
Gas Safe and G3 qualified engineers across SW3, SW7 and SW10, 24 hours a day.
Answered 24 hours a day by a technical customer service member.
Where a basement has been dug out, the heating usually serves two very different circuits from one boiler.
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.
Two details to start. Add your postcode and whether there is a cylinder in an airing cupboard and we can usually tell you the likely part before we attend.
We cover Chelsea, and the whole of London
Tell us the address and you will get an honest answer about timing.
View areas we coverThree steps. The first one usually tells us most of it.
If a repair is not worth doing, we will say so on the phone. Call 0203 868 6134.
Almost nobody says they live in SW3. They say the Boltons, or off the Kings Road, or South Ken.
Names we hear on SW3, SW7 and SW10 calls, and the postcodes around them
Grouped by postcode, because that is the one part of an address everybody knows.
We work right across London, north and south of the river. If yours is not here, ring and tell us the address.
And they want different temperatures.
SW3, SW7 and SW10 have had more basement excavation than anywhere else in the country. A dug-out lower ground almost always gets underfloor heating, because there is no wall space and a stone floor needs it. The rest of the house keeps its radiators.
Those two circuits want different water. Radiators are sized for water around 55 to 70 degrees. Underfloor runs at roughly 35 to 45, because anything hotter is uncomfortable underfoot and can damage a stone or timber floor. One boiler produces one flow temperature.
The join between them is a blending valve and a separate pump on the underfloor manifold, with its own control. Where that was fitted properly it is invisible. Where the underfloor was added later and simply teed off the existing pipework, you get a floor that is too hot or radiators that never get hot enough, and no amount of work on the boiler resolves it because the boiler can only be right for one of them.
A blending valve on the underfloor manifold is a small brass part with a temperature dial on it. If your lower ground has underfloor heating and you cannot find one, that is worth knowing before anybody quotes to replace a boiler for not heating the house evenly.
The commonest call from SW3, and it is rarely the boiler.
On a stored system, heating that works and hot water that does not points at the cylinder side. Three usual culprits: the motorised valve that diverts flow to the tank, the cylinder thermostat, and the immersion element. Each costs a fraction of a new appliance and each gets mistaken for one.
Houses with a dug-out basement usually gained a much larger unvented cylinder at the same time, sized for several bathrooms. A tank that size takes a long time to recover, so a morning where the last shower runs cold is often a recovery question rather than a fault, and the answer is the cylinder thermostat setting and the coil rather than a new boiler.
An unvented cylinder is a pressurised store, so working on one is notifiable and needs a G3 qualification on top of Gas Safe registration. Plenty of firms hold one and not the other, which is why a cylinder call so often becomes two visits. Our engineers hold both, so it is one visit and one charge. See unvented cylinder repair.
On underfloor it does something else again.
London water comes off the Thames and the Lea, both of which run through chalk. It measures roughly 277 milligrams of calcium carbonate per litre, and that figure is much the same across the city.
Where it lands is what differs. In a combi it furs the plate heat exchanger. On an unvented cylinder it coats the coil so the tank recovers more slowly. On underfloor pipework it is magnetite rather than scale that causes trouble, settling in long low-flow circuits buried in screed where it cannot be reached, which is exactly why a filter matters more on these systems than on a house full of radiators.
Age does not decide it. The failed part does.
A pump, a diverter valve, a thermostat or a fan is a repair on almost any appliance, whatever its age. A failed main heat exchanger on a boiler well past ten years is the point where the arithmetic stops working, and we will tell you that rather than sell you the repair.
In a house with underfloor and radiators the replacement question is really a controls question. A new boiler still produces one flow temperature, so if the blending and the zoning are wrong they will be wrong afterwards too. Putting that right is a fraction of the cost and it is the only way to know whether the appliance was ever the problem.
Our boiler replacement page sets out what a replacement actually involves, including what changes when a stored system is converted, and the costs guide explains what moves the figure.
That answer costs nothing. It is the one most people ring us for. Call 0203 868 6134.
Next door to here we cover Belgravia, Mayfair and Knightsbridge and Notting Hill and Holland Park. Everything else is on boiler repair in north London and areas we cover.
These are where we work most, not a boundary. An engineer attends anywhere in north London and south London. Tell us where you are and we will say plainly when we can get to you.
Underfloor downstairs, radiators above?
Those two want different water temperatures from the same boiler. If one is right the other is wrong, and that is a controls job rather than an appliance one.
If you smell gas: do not touch any switches. Open the windows, leave the property, then call the National Gas Emergency Service on 0800 111 999. That line is free and open 24 hours. Call them before you call us.
If a carbon monoxide alarm is sounding: get everyone out immediately, then call 999 if anyone feels unwell. Do not go back in until the property has been ventilated and checked.
If the boiler locks out repeatedly: try one reset. If it locks out again straight away, stop. Repeated resets hide a fault that is still there, and on a gas appliance that is not a risk worth taking.
Under the Gas Safety (Installation and Use) Regulations 1998, only a Gas Safe registered engineer may work on gas appliances. Never open the boiler casing yourself.
Yes. The names listed above are the ones we hear most, and they are nowhere near a complete list. We work right across London, north and south of the river. Ring and tell us the address and you will get a straight answer about timing.
Because one boiler makes one temperature and those two circuits want different ones. Radiators need water around 55 to 70 degrees, underfloor around 35 to 45. If the boiler is set low enough for the floor, the radiators will always disappoint. The fix is a blending valve and separate control on the underfloor, not a new boiler.
No, and it can damage a stone or timber floor over time. It usually means the underfloor circuit is being fed straight from the boiler without a blending valve to bring the temperature down. That is a manifold job and it is a great deal cheaper than the floor.
Sometimes, but more often it is recovery rather than capacity. A large unvented cylinder takes a long time to reheat, and a scaled coil or a low thermostat setting makes that worse. Both are checkable before anybody discusses a bigger tank.
Almost certainly not. That points at the cylinder side: the motorised valve that diverts to the tank, the cylinder thermostat, or the immersion element. Our unvented cylinder repair page explains what is involved.
Yes, and every other major make, including the ones most firms will not touch. Those two and Viessmann are what we open most in SW3, SW7 and SW10. Keston appears in basement plant rooms, and Alpha, Main, Ariston, Ferroli, Vokera and Biasi turn up in the flats and mews. If your boiler is showing a code, the brand pages explain it.
Yes, and on the same visit where the appliance passes, so a let property is not off the market twice. See landlord gas safety certificates. If it has no gas supply we cover electric boilers as well.
The line is answered 24 hours a day by a technical customer service member, not a call centre reading from a script. In the middle of the night we will tell you honestly whether it is a tonight job or a first thing in the morning job.
Every major make, and the fault code pages often name the part before you ring.
Houses this size run system boilers feeding a large unvented cylinder, and here that is mostly Worcester Bosch, Vaillant and Viessmann, with Keston appearing where a basement plant room needs an unusual flue.
We also work on the makes most firms will not: Alpha, Main, Ariston, Ferroli, Vokera and Biasi all turn up in the flats and mews, and parts for every one are still obtainable.
If your boiler is showing a code, the make decides what it means. A Vaillant F75 and a Worcester Bosch EA are different faults with different fixes. Each brand page lists the codes for that make and what causes them.
The full list is on our boiler brands page, and general repairs are on boiler repair in London.
Tell us where you are and whether there is a 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.
