5 Things to Check Before Turning on Your Boiler
If your boiler fails on the first cold day, repair bookings can take days. Here are checks you can do yourself in autumn and signs you need a professional.
A boiler rests for months, then suddenly has to work hard on the coldest day. That is why breakdown calls spike in the first cold week. Switch it on and check it while it is still mild, and you avoid waiting days for a repair when you really need heat.
This article covers only visual checks you can do at home. Never work on gas lines, open up the boiler or replace parts yourself; leave that to the manufacturer’s service or your gas supplier.
1. Clear and ventilate the boiler area
Move boxes, cleaners, aerosol cans and laundry away from the boiler. Flammable items nearby are dangerous, and clutter can stop the boiler drawing in enough air. Check that vents and windows are not blocked.
2. Check the flue
Look at the flue pipe leading from the boiler and check that it is not disconnected, gapped at the joints or patched with tape. The flue carries combustion gases outside; a gap can let carbon monoxide into your home. If anything looks wrong, do not switch the boiler on and call for service. A carbon monoxide alarm near the boiler adds peace of mind.
3. Check system pressure
Check that the pressure shown on the display or gauge is within the manufacturer’s recommended range. If it asks you to top up, follow the manual. If you need to top up often, there may be a leak somewhere, so have it inspected.
4. Do a test run
Turn the heating on for about 30 minutes and check three things:
- Unusual noises such as banging or whistling
- Drips under the boiler or at pipe joints
- Error codes on the display
Error codes are explained in the manual or on the manufacturer’s website. Codes that do not clear after a restart usually need a service visit.
5. Check every room warms up
During the test run, feel the radiators or floors in each room. If one room stays cold, a valve may be closed or there may be air in the system. Check the valve first, and if it still does not heat, ask a heating engineer to look at it.
Call a professional right away if
- You smell gas → shut off the gas, open windows, do not touch electrical switches, leave and call your gas supplier or emergency services.
- The flue is disconnected or corroded
- Water keeps leaking from the boiler
- It is more than 10 years old
Once the boiler check is done, dust the window tracks and curtains before the heating season too. With windows closed, dust lingers indoors longer.
