Winter Boiler and Heating Checklist 2026: What to Do Before the Cold Sets In

Short answer: book an annual boiler service, bleed your radiators, check your system pressure and locate your stopcock before the weather turns — all straightforward jobs that catch most winter breakdowns before they happen.

Book the annual service now, not in December

Gas Safe registered engineers get booked out fast once the first cold snap hits, so early-to-mid autumn is the best time to get a boiler serviced. A service checks the burner, flue and safety devices, and catches small faults — a failing pump, a worn seal — while they're still cheap to fix. See our guide to signs your boiler needs replacing if yours is showing its age.

Bleed your radiators

If the top of a radiator stays cold while the bottom heats up, there's trapped air in the system, and it's an easy DIY fix with a radiator key. Bleeding radiators before you switch the heating on properly for the season means you're not troubleshooting a cold spot on the first freezing night.

Check your system pressure

Most modern boilers have a pressure gauge on the front. It should typically sit between 1 and 1.5 bar when the system is cold — check your boiler's manual for the exact figure. Low pressure is one of the most common reasons a boiler stops firing, and topping it up is usually a five-minute job with the filling loop.

Know where your stopcock is

If a pipe does freeze and burst, being able to shut off the water supply immediately is the difference between a minor repair and a flooded property. Find your stopcock — usually under the kitchen sink or near where the water main enters the house — before you need it in an emergency, not during one.

Warning signs worth acting on now

• The boiler is making banging, gurgling or whistling noises
• The pilot light burns yellow or orange instead of blue
• You've needed a call-out more than once in the past year
• The boiler is over 10-12 years old

Any of these are worth a proper look before winter, not after a breakdown. Our boilers and heating team can service, repair or advise on replacement, and if you're weighing up a heat pump instead, our piece on heat pump grants in 2026 covers what's currently available.

This is general seasonal guidance for the South East of England, and the right timing for your own property depends on its specific condition, aspect and exposure. Get in touch if you'd like us to take a look before the weather turns.