Boiler Repair & Boiler Service in London

Common boiler faults we diagnose

Modern combi and system boilers report faults through error codes. The code points to a system, not always the exact part, so we test before replacing anything.

• ✓ Low pressure (below 1 bar): often a small leak, a weeping pressure relief valve or a failed expansion vessel charge
• ✓ Ignition / flame failure: gas supply, ignition electrode, flame sensor or gas valve
• ✓ Frozen or blocked condensate pipe: very common in London winters on external pipework
• ✓ Diverter valve faults: heating works but no hot water, or the reverse
• ✓ Pump and fan faults: noise, overheating and lockouts
• ✓ Kettling and banging: limescale or sludge in the heat exchanger

What an annual boiler service covers

A yearly service keeps the boiler efficient, catches worn parts early and is usually required to keep a manufacturer warranty valid.

• ✓ Visual check of the case, seals, flue and terminal
• ✓ Combustion analysis with a flue gas analyser
• ✓ Cleaning of key parts and checking the condensate trap
• ✓ Checking pressure, expansion vessel and safety devices
• ✓ Written note of findings and any recommended repairs

Repair or replace?

We don't push replacements. If a boiler is safe and parts are available, a repair is often the sensible choice. We'll be honest if repeated failures, age or efficiency make replacement better value.

Combi, system and regular boilers explained

Knowing your boiler type helps us diagnose faster and recommend the right parts.

• ✓ Combi: heats water on demand, no hot water cylinder; common in London flats
• ✓ System: heats a sealed hot water cylinder; good for homes with more than one bathroom
• ✓ Regular (heat-only): uses a cold water tank in the loft plus a cylinder; common in older houses
• ✓ Normal working pressure on sealed systems is usually 1 to 1.5 bar when cold

Checks you can safely do before calling

These simple checks sometimes restore heating without a visit. Never remove the boiler casing yourself.

• ✓ Check the pressure gauge and top up to about 1.2 bar using the filling loop if you know how
• ✓ Make sure the power, timer and thermostat are on and set high enough
• ✓ In freezing weather, pour warm (not boiling) water over the external condensate pipe
• ✓ Press reset once; if it locks out again, stop and call