Buying a boiler-servicing contractFAQs

How much does annual breakdown cover cost?

Costs can vary from around £80 to over £300 depending on the level of cover you take out.

What different types of annual breakdown cover are there?

Choose a boiler-servicing policy that includes annual maintenance

You can get breakdown cover without annual maintenance, but we would recommend only choosing a policy that includes it. The annual service or maintenance includes important safety and performance checks to ensure your boiler is running safely and smoothly.

The most basic annual breakdown cover will just include your boiler. However, many providers offer an array of additional cover options, including repairs for central heating, plumbing and drains and even your electrical wiring.

How old should my boiler be before I take out breakdown cover?

While boilers are more likely to break down the older they get, reliability research carried out by Which? suggests one in three boilers will break down within the first six years.

For added peace of mind, you can take out your breakdown cover when your manufacturer’s warranty has finished. This is usually one to three years after you’ve purchased your boiler.

What amount of cover is best for me?

This will depend on your individual circumstances. In our survey of Which? members, most people cited the added peace of mind as the main reason for taking out boiler cover.

For some, the extra security of taking out more comprehensive cover to include central heating, pipes and drainage will be reason enough.

However, while our research suggests boiler breakdown is a relatively common problem, we have no evidence to suggest problems with for example pipes and drainage systems warrants taking out the extra cover.

What are the most common boiler problems, and how much will they cost to repair if I'm not covered?

Our expert, Corgi registered gas engineer Brian Philmore, has rated the common boiler faults in order of the problems he most commonly faces.

Printed circuit board

£220 to replace. The PCB is the heart of the boiler, connecting everything together. Without it the boiler can’t function.

Automatic air vent

£85 to replace. An automatic air vent lets out air that collects within the boiler.

Pump

£200 to replace. The pump moves the heated water from the boiler through the pipe work to the radiators, and back to the boiler for re-heating.

Overheat thermostat

£95 to replace. The overheat thermostat is a safety device to stop the boiler overheating if the control thermostat fails.

Heat exchanger

£350 to replace. Heats the water by transferring energy from the gas, if this goes it can be very expensive to replace.

Expansion vessel 

£140 to replace. The expansion vessel stops the heating system from being over-pressurized.

Gas valve

£180 to replace. The gas valve regulates the flow of gas to the burner.

Burner

£150 to replace. Mixes air and gas to be burned inside the boiler.

Notes

All repairs include call out, parts and labour. Cost estimates are guide prices only provided by Npower. However, as previous Which? research has shown the cost of hiring a plumber (plumbers must be Corgi registered to work on your boiler) can vary widely across England, Scotland and Wales.