5 Signs Your Boiler Needs Service Before Winter

Your boiler works hardest when temperatures drop. The worst time to discover a problem is the first cold morning of the year, when every repair shop in the area is already backed up.

These five warning signs usually show up before a complete breakdown. Catching them early is cheaper and less disruptive than an emergency call.

1. The boiler is making new noises

Banging, kettling, or a low rumbling sound from the boiler are not normal. Kettling — a sound like water boiling in a kettle — usually means limescale buildup on the heat exchanger. Banging can indicate a faulty pump or a problem with the expansion vessel. Neither gets better on its own.

2. Rooms heat unevenly

If some radiators stay cold while others get hot, the system may need balancing, or a zone valve could be failing. Sludge buildup in older systems causes the same problem and is fixed with a power flush.

3. Your gas bill is climbing

A boiler working harder to produce the same heat is losing efficiency. This often means the heat exchanger is fouled, the burner needs cleaning, or the unit is approaching the end of its service life.

4. The pilot light keeps going out

A pilot that will not stay lit points to a faulty thermocouple, a blocked pilot tube, or a draught problem. It is a simple repair when caught early. Ignoring it means the boiler eventually stops working entirely.

5. The pressure drops repeatedly

Boilers need to maintain pressure between 1 and 1.5 bar. If yours keeps dropping, there is a leak somewhere in the system — either at a radiator valve, a pipe joint, or the boiler itself. Topping up the pressure manually is a short-term fix, not a solution.

The right time for a service is before any of these happen. An annual tune-up costs a fraction of an emergency repair and adds years to the boiler's life. If you are seeing one or more of these signs, call before the first cold snap.