How to fix or replace a boiler and look after it over the winter months

You may not need a winter coat for a few weeks yet, but autumn is the best time to make sure your central heating system is in tip-top condition ready for the cold days ahead.

Related: How to keep your house warm in winter

Whether you need to fix, service or replace a boiler, or just want to slash your bills, we have all the advice you need.

Can I fix a boiler without calling an engineer?

Absolutely, but don’t try anything beyond these basic checks. Firstly, if you're on a repayment meter, check your credit, turn on any gas appliances to check for a flame, and see if a fuse has tripped.

Power cuts can reset timers, so you may need to reprogramme it. Once you've done it, turn the thermostat up past 21˚C, which can force the boiler into action.

Is my boiler pressure too low or too high?

Checking and topping up your boiler's pressure is simple – search British Gas: 
How to Check Water Pressure on YouTube. Finally, press your boiler’s Reset button, because sometimes turning it off and on again really is the answer!

Is an annual boiler service really necessary?

We think so. A yearly service by a Gas Safe Registered engineer is just common sense. Boiler servicing costs usually costs between £60 and £100. That's way less than any potential charge should things go wrong in an emergency.

The engineer should check the flue (both inside and outside the house), operating pressure and heat output and all seals. They should also do a full safety check and clean parts if necessary, plus provide a signed service report.

Our boiler cuts out in really cold weather – is it a fault?

Below-zero weather can cause condensate pipes (found on modern condensing boilers) to freeze, which can stop the boiler from working. It's a common call-out in the winter. Simply defrost the pipe by pouring some warm (not boiling) water over it.

I’ve got an A-rated boiler and but the bill is still high. Any tips on cutting it down?

Boilers account for up to 60 per cent of our annual energy bills, and even if you never have the heating over 20°C,your bill may still be high.

Doing the hard part and getting 
a high-efficiency boiler installed can cut up to £570 a year compared to an older model. but nstalling a programmable thermostat (from £35, screwfix.com) and thermostatic radiator valves (TRV, from £5 each) to each radiator can also chop £150* from your bill by letting you control when and where the heating is used. But remember, your home needs to be properly insulated.

Is it worth installing a smart thermostat?

Flashy new thermostats like Nest and Hive give you more control over your heating via smartphone, and can track gas usage. The leading brands also promise quite impressive savings. Remember, however, these are not guaranteed.

The new Bosch EasyControl from Worcester Bosch can help you control and even zone your home (when paired with Bosch Smart Thermostats) via an app on your smartphone or tablet. Expect to pay around £360 for a Bosch EasyControl package with three Bosch Smart Thermostats.

How much is a new boiler?

Replacing a gas fired boiler, you can expect to pay around £2,500, depending on the location, property and installer.

How often should I bleed the radiators?

Related: How to bleed a radiator: our step-by-step guide

Your radiators will need bleeding after a few months of not being used and it’s easy to do yourself, assuming you can find where you left the radiator key. Buy one now and put it somewhere safe for when you need it.

*According to the Energy Saving Trust