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Planned work · London · from £110 first hour

Central Heating Repair in London

Cold radiators with a hot boiler is a circulation problem, air, sludge, a stuck valve or a tired pump.

Get a fixed quote Or call 020 3674 8514
Central heating repair in London
No call-out feeNo night or weekend surchargeFixed price before we start12-month workmanship guarantee

The pattern of which radiators are cold tells most of the story before we even arrive.

What you get

Central heating repair in London: what the price includes

  • 01
    Diagnosis by pattern

    Cold at the top: air. Cold at the bottom: sludge. Cold at the far end: balancing or pump. Random: motorised valve. We read the system, then fix it.

  • 02
    Pumps and valves

    Circulators, zone valves and actuators carried for same-visit replacement.

  • 03
    Balancing done properly

    Whole-system balancing so the far bedroom finally warms without cooking the hallway.

  • 04
    Controls upgrades

    Failed programmers and thermostats replaced, smart controls fitted where they genuinely help.

  • 05
    Diagnosed as a system, not as a symptom

    One cold radiator is a balancing or valve problem. Cold at the bottom across several is sludge. Cold at the top is air. Everything cold is a pump, a valve or a control. We establish which pattern yours is before anyone starts bleeding radiators at random.

What this means in London

Local conditions we work around

Hard water is the defining fact for London heating. At 280 to 320 ppm, scale builds on the hottest surface in the system, which is the boiler heat exchanger, and every millimetre of it costs efficiency and shortens the life of the unit. It is why we flush before commissioning a new boiler, why we fit a scale reducer on the mains where the system warrants it, and why an unvented cylinder in London needs its annual service rather more than the manual implies.

Where we do this in London

Covered across London

Same published rate card and the same twelve-month workmanship guarantee everywhere below, there is no postcode loading. Each area has its own page with an arrival time taken from our job records rather than chosen for a website.

UpminsterDartfordGravesendOrpingtonSevenoaksEpsomSuttonKingstonSurbitonWokingStainesUxbridge All London areas →
Straight answers

Central heating repair in London, your questions

Some radiators are hot and some cold, why?
If the cold ones are furthest from the boiler, the system needs balancing or the pump is tiring. If they're cold at the bottom, sludge has settled, that's a flush. Top-cold is just air: bleed them first, it's free.
What does a typical circulation repair cost?
Standard rate card: £110 first hour, most valve/pump swaps completed within it plus parts. Balancing a whole system is usually one visit.
Is banging or kettling serious?
Kettling (a boiling-kettle rumble) means scale on the heat exchanger working as insulation, it shortens boiler life meaningfully. A cleanse now beats an exchanger later.
Why is one radiator always cold?
Cold at the top means air, and bleeding it fixes it. Cold at the bottom means sludge sitting in the panel and needs flushing. Cold all over usually means a seized thermostatic valve pin, which is a five-minute fix once identified.
My upstairs is hot and downstairs is cold.
That is a balancing problem, and it is very common after a boiler change. The lockshield valves need setting so flow is shared correctly rather than taking the path of least resistance. It is an adjustment, not a repair, and no parts are involved.
Do I need a magnetic filter?
In London we would say yes on any system over ten years old. It catches the iron oxide that causes cold spots and eventually kills pumps and heat exchangers, and it is cheap next to what it prevents. In soft-water areas it matters more than a scale reducer.
How does London hard water affect heating work?
Considerably. Scale builds on the hottest surface in the system, which is the boiler heat exchanger, and every millimetre costs efficiency and life. It is why we flush before commissioning a new boiler here, why kettling is the most common noise complaint we get in London, and why an unvented cylinder in this city genuinely needs its annual service rather than nominally needing it.
24 hours · 365 days · London

Water where it
shouldn't be? Call.

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020 3674 8514

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