Pump replacement
The working heart of the system, and the most common cold-season failure; supplied and fitted.
£200 to £350
24/7 Emergency Line, engineers on standbyAll 32 London boroughs
Gas Safe Registered12-month guarantee · No call-out fee
SAME-DAY APPOINTMENTS · FIXED QUOTES · WHOLE-SYSTEM SPECIALISTS
Central Heating Repair in London
A boiler can be running perfectly and your house can still be cold, because the boiler is only the engine. The heat has to travel: through pumps, valves, thermostats, pipework and radiators, and any one of them can quietly sabotage the lot. Our Gas Safe engineers repair the whole central heating system across every London borough: cold radiators brought back to life, seized pumps replaced, motorised valves freed, thermostats and smart controls fitted and fixed, airlocks cleared and systems balanced so every room finally reaches the temperature on the dial. Same-day appointments, fixed quotes before any work starts, and a 12-month guarantee on every repair.
Engineers online now
24/7Get a free callback
Average reply under 10 minutes. No obligation.
Call 020 3000 0000or request callback
Gas Safe
1-hour response
No call-out fee
The circuit
The system around the boiler, and why it fails
Central heating is a circuit, and circuits fail at their weakest point. In London's housing stock that point is rarely the boiler itself. It is the pump that seized over summer and announces itself on the first cold morning of October. It is the motorised valve stuck halfway, giving you hot water but no heating, or the reverse. It is the thermostat losing its connection so the boiler never hears the house asking for heat, the TRV pin jammed shut behind the sofa, the airlock sitting at the top of a towel rail, or the slow build of sludge that turns the ground-floor radiators lukewarm while upstairs boils. Our engineers diagnose the circuit as a whole, which is why the fix is usually found in one visit rather than three.
The system around your boiler
- PumpPushes hot water round the circuit
- Motorised valvesDirect heat to radiators or hot water
- Thermostat and controlsThe brain
- TRVsPer-radiator temperature control
- PipeworkThe arteries
- RadiatorsWhere the heat finally arrives
Diagnostics
What your radiators are trying to tell you
Symptom
What it usually means
Action
Cold at the top of the radiator
Trapped air; needs bleeding, and if it recurs, air is being drawn in somewhere
BLEED & TRACE Common repairs
The repairs we carry out every day
Motorised valve
Two-port and three-port valves that direct heat, repaired or replaced with a fixed quote.
£150 to £280
Thermostat & programmer
From rewiring a loose connection to replacing the unit. We will tell you when the honest answer is a £15 battery.
£90 to £200
TRV replacement
Seized or failed radiator valves swapped, often several in one visit.
From £75
Radiator repair & replacement
Leaking, corroded or undersized radiators replaced and balanced in.
Quoted per rad
Balancing & airlock clearing
The whole-house tune that makes every room reach the temperature on the dial.
£95 to £160
Smart heating
Smart controls, fitted properly
Half of London now runs its heating from a phone, and half of those installations were done by whoever was cheapest. We fit and fault-find Hive, Nest, Tado and Honeywell controls, wire them correctly to the boiler they are actually paired with, and set schedules that reflect how the household really lives. Done properly, a smart thermostat trims real money off a gas bill; done badly, it is a £200 ornament that argues with the boiler. If yours has never quite worked since the day it went up, that is a one-visit fix.
HIVENESTTADOHONEYWELL
The honest bit
When it is not a repair: the sludge conversation
Sometimes the engineer's honest finding is that no single part is broken; the system's water is. Years of magnetite sludge strangle flow, cool radiators from the bottom up and shorten the boiler's life, and no amount of valve replacement fixes dirty water. That is the point where we talk about a power flush, and we will only have that conversation when the evidence supports it. The full picture, including when a flush is genuinely needed and when it is being over-sold, lives on our power flushing page.
Read about power flushingRecent work
Recent heating repairs across London
JOB / SW17 / PUMP
A Tooting terrace, SW17: no heating on the first cold Saturday of autumn, seized pump diagnosed on the phone from the symptoms, replaced from van stock before lunch.
JOB / N4 / BALANCING
A Finsbury Park conversion, N4: three cold bedrooms above a boiling ground floor, full system balance and two TRVs, every room within a degree of target by evening.
JOB / E11 / CONTROLS
A Leytonstone semi, E11: a smart thermostat that had never once matched its schedule, rewired and re-paired in forty minutes, gas bill visibly down the following month.
Central heating repair in London, your questions answered
Try bleeding it first; cold at the top is usually just air, and it is a five-minute job with a radiator key. Cold at the bottom, or a radiator that needs bleeding constantly, is worth a visit.
Every room warm, this week
Cold rooms, cold radiators, controls that ignore you: one visit usually settles it. Call 020 3000 0000 or request a callback, describe the symptom, and we will tell you before we come out whether it sounds like a five-minute bleed or an engineer's job.