WHAT ARE THE MOST COMMON FAULTS WITH BOILERS TODAY?

All boilers will need repairing at some point. If boilers are not regularly serviced issues will arise more quickly.

There are certain faults which are common to all boiler manufacturers such as pressure problems or blocked condensates. Then there are those faults particular to each manufacturer. Here we give you a description of the most common repairs for each manufacturer.

Vaillant​

Leaking diverter valve – commonly leaks from the spindle moving the valve from heating to hot water position.
Printed Circuit Board – these issues most often present as intermittent F-code errors.

Worcester

Fan baring plate – a loose flap between the fan and the burner which can stick, causing ignition faults.
Leaking flow sensor – an adaptor which attaches to the hot water flow detector can become brittle and crack causing a leak.

Idea

Spark generator – this part creates the current that generates a spark to light the burner. If it fails, the boiler will show an ignition fault.
Leaking sump – an expensive repair requiring a new primary heat exchanger.

Glowworm

Leaking manifolds – the plastic connector at the back of the boiler can develop a hairline crack and start to leak.
PCB – normally presents as a completely blank display screen. Very common on older models.

Baxi

Circuit board, fan, burner assembly – when newer Baxi models fail, they require a unit that contains 3 separate components to be replaced – quite expensive if the boiler is outside the warranty period. 

Viessmann

Blocked heat exchanger pipes – older models have rubber tubes that connect the flow and return pipes to the heat exchanger. These often become blocked with rust and other particles from the heating circuit.
Parts availability – historically, some Viessmann parts took 2 weeks to be delivered from Germany.

Vokera

Cracked heat exchanger – some models develop corrosion on their primary heat exchangers – an expensive and sometimes terminal failure.
Fan failure – presents with A-code and causes total outage of the boiler.

Most faults listed are easily repairable and may be covered by the manufacturer’s warranty. Repairs must only be carried out by a Gas Safe registered engineer.

Depending on the age of the boiler and the cost of the repair, you may decide that it’s better to replace the boiler. If we attend your fault, we will give you an honest assessment of the condition of the boiler, the cost to repair and the cost and benefits of replacement, to allow you to make an informed choice.

You can also check out our Quick Quote page to get an idea of the cost of an new boiler in just a few minutes.