Maintenance
Boiler Maintenance Checklist: Simple Checks Between Services
Reviewed by our Gas Safe registered engineers · Last updated 22 July 2026
An annual service is essential, but a few simple checks through the year keep your boiler running smoothly and catch small problems early. Here’s a homeowner’s checklist of what to look at, how often, and when to call us.
Quick answer: Between annual services, glance at the pressure gauge monthly (keep it around 1–1.5 bar), bleed radiators at the start of the heating season, check the flame is crisp blue, keep the boiler and its vents clear, and run the heating briefly in summer to stop the pump seizing. None of these replace a Gas Safe service — anything involving the gas, the flue, or removing the boiler casing is for an engineer — but they keep things ticking over and flag problems early.
The Checklist
What to check, and how often
A quick routine that keeps a boiler healthy between services and catches the small stuff early.
| Check | How often | What you’re looking for |
|---|---|---|
| Pressure gauge | Monthly | Around 1–1.5 bar; top up if it’s low |
| Radiators | Start of heating season | Cold at the top means bleeding; black water means sludge |
| Boiler flame | Occasionally | Crisp blue, not yellow or orange |
| Vents & flue outlet | Occasionally | Clear of leaves, debris and blockages |
| Run the heating in summer | Monthly in warm months | Stops the pump and valves seizing |
| CO alarm | Test monthly | A working, in-date audible alarm |
| Condensate pipe | During cold snaps | Not frozen; lag any exposed external run |
Who Does What
What you can do, what we do
Safe for you to do
- Check and top up the pressure to 1–1.5 bar
- Bleed radiators that are cold at the top
- Glance at the flame colour and keep vents clear
- Test the CO alarm and run the heating briefly in summer
Leave to a Gas Safe engineer
- Anything involving the gas supply or the flue
- Combustion checks and flue-gas readings
- Removing the boiler casing or internal cleaning
- The annual service that keeps the warranty valid
Engineer Insight
The two checks that matter most
The two checks that save people the most grief are pressure and the summer run. A quick monthly glance at the gauge means you catch a slow leak before it locks the boiler out on the first cold morning of the year. And firing the heating for a few minutes in summer stops the pump seizing after months of standing still — a stuck pump is one of the most common ‘it worked in spring’ autumn breakdowns we get called to. Neither takes two minutes.
Costs
When it's time to call us
Typical North London guide prices — you’ll always get an upfront quote before any work starts.
FAQs
Boiler maintenance — your questions answered
What boiler maintenance can I do myself?
Check and top up the pressure, bleed radiators, glance at the flame colour, keep vents and the flue clear, test your CO alarm, and run the heating briefly in summer. Anything involving gas, the flue, or the boiler casing is a job for a Gas Safe engineer.
How often should I check my boiler pressure?
Monthly is a good habit, and any time a radiator’s been bled or the heating’s been off a while. Keep it around 1–1.5 bar cold; top up with the filling loop if it drops below 1.
Why should I run my heating in summer?
Running the heating for a few minutes each month in warm weather stops the pump and valves seizing from standing still — one of the most common causes of a boiler failing on the first cold day.
Does home maintenance replace an annual service?
No. These checks keep things ticking and catch problems early, but only a Gas Safe service inspects combustion, the flue and internal components — which is what keeps the boiler safe and your warranty valid.
How do I stop my condensate pipe freezing?
Lag any external run of the white plastic condensate pipe with proper pipe insulation. In a hard frost you can thaw a frozen one with warm (not boiling) water, but insulating it is the real fix.
Related
Related guides
Why the yearly service matters.
Read guideMaintenanceSigns Your Boiler Needs ServicingHow to tell yours is overdue.
Read guidePressureBoiler Losing PressureWhen topping up isn’t enough.
Read guideRadiatorsHow to Bleed a RadiatorStep-by-step for cold-topped radiators.
Read guideEmergencyCarbon Monoxide Warning SignsWhy the CO alarm check matters.
Read guideCentral HeatingCentral Heating Pump GuideThe pump that seizes if it sits idle.
Read guideBrowse all Maintenance guides, or head back to the Help & Advice Centre.
Due a service, or spotted a problem? Call us.
Book an annual service or a repair with a Gas Safe engineer, or call for advice on any of these checks. North London, upfront pricing.
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