The mornings have gone cool, the heating has fired once or twice by accident, and the first leaves are already in the gutter. September is the most useful month in the British homeowner’s year — and the one most people spend doing nothing. Good september home maintenance is not about bracing for winter in the abstract. It is about a fixed deadline: the clocks go back on 25 October 2026, and almost everything on this list is easier, cheaper or simply possible in daylight.
The short answer
You have roughly eight weekends. Eleven jobs, four of which need a trade booked now and seven of which you can do yourself. The trade jobs — boiler service, chimney sweep, gutter clearing and any external repair — all get more expensive and harder to book from mid-October onwards, because that is when everyone else notices. The DIY jobs mostly take under an hour each and are worth doing in the order below.
Heating: three jobs before the first cold snap
1. Book the boiler service. If it has not been serviced this year, September is the last comfortable month to get an appointment at a normal price and a date of your choosing. Expect somewhere in the region of £80–£120 for a standard gas combi outside London, and insist on a proper service with combustion checks rather than a visual once-over. Use a Gas Safe registered engineer and check the registration number before they start.
2. Bleed and balance the radiators. Run the heating for twenty minutes, then feel each radiator top and bottom. Cold at the top means trapped air and a bleed key fixes it in two minutes. Cold at the bottom means sludge, which does not fix itself and is worth mentioning when the engineer visits. Balancing — adjusting the lockshield valves so the far radiators heat at the same rate as the near ones — is the single most underrated free job in this list.
3. Reset the heating controls. Thermostats and timers still holding last winter’s schedule waste money quietly for months. Set the times you actually want now, check every thermostatic radiator valve turns freely, and put the unused rooms down rather than off.
Fire, fumes and the first log
4. Test every smoke and carbon monoxide alarm. Press the button on each one. Replace the batteries in anything that hesitates and replace the unit entirely if it is more than ten years old — the sensors degrade whether or not the battery is fresh. Carbon monoxide alarms matter most in the weeks the heating restarts, which is precisely now.
5. Book the chimney sweep before you light anything. If you have a working fireplace or a wood burner, it should be swept before the first fire of the season, not after the first smoky one. Sweeps book solid from October. A sweep also gives you a certificate, which some insurers ask for after a chimney fire.
Keeping the water where it belongs
6. Clear the gutters and check the downpipes. Do this after the first proper leaf fall, not before, or you will be doing it twice. If you are not confident on a ladder, this is the job to hand over — and September is when a roofer can still fit you in.
7. Lift the drain gully covers. Ten minutes with gloves and a trowel on the gullies and any external drain covers prevents the overflow that soaks a wall all winter. Rainwater running down brickwork rather than through a pipe is the origin of a surprising share of “rising damp” call-outs.
8. Find your stopcock and lag the exposed pipes. Everyone means to do this in December, in the dark, with water coming through the ceiling. Locate it, label it, make sure it turns, and put foam lagging on any pipework in the loft, garage or an unheated utility.
The daylight jobs
9. Do the outside repairs while it is still dry. Repointing, sealant around window frames, fascia paint and any small roof repair all need dry, frost-free weather to cure properly. In a 1950s semi in Berkshire, a half-metre of failed pointing left until December became a damp chimney breast by March. September is the last reliable window.
10. Sort the lighting and the timers. After 25 October you come home in the dark. Check external and security lights work, replace the failed bulbs while you can see what you are doing, and set any lamp timers now rather than in November.
The five-minute paperwork job
11. Check the energy tariff and the insurance renewal. The energy price cap changes at the start of October, so it is worth knowing which tariff you are on before your usage triples. While you are there, check what your buildings insurance actually says about escape of water and unoccupied periods — most people discover the answer at the worst possible moment.
Black mould in a British house is almost never a building fault. It is a ventilation habit. The first three weeks of heating are when condensation reappears, and the instinct is to seal the house up tighter. Do the opposite: run the extractor for ten minutes after every shower, keep trickle vents open, and leave a gap behind furniture on external walls. Insulate and ventilate together, or you get warm, wet air and a black corner by Christmas.
What to do in the next 30 minutes
Phone for a boiler service appointment. This is the one that gets harder every week you leave it.
Press the test button on every smoke and carbon monoxide alarm in the house.
Find the stopcock, turn it once, and label it.
Walk the outside of the house and look at the gutters, downpipes and gully covers. Photograph anything that looks wrong.
Set the heating timer to this winter’s schedule rather than last winter’s.
Diarise the four trade jobs with a deadline of the clocks going back.
Save the September list to Home+
Eleven jobs is exactly the number that gets forgotten by the second weekend. A free Home+ logbook lets you save the September list, tick the jobs off as you go, and keep the boiler service certificate, the sweep certificate and the engineer’s registration number against your property rather than in a kitchen drawer. Next September, the list is already there and half of it is already dated.
Frequently asked questions
When do the clocks go back in 2026?
British Summer Time ends on 25 October 2026, when clocks go back one hour at 2am. Everything on this list that needs daylight or dry weather is easier before that date.
What is the most important September home maintenance job?
The boiler service, on two counts. It is the only job on the list with a safety element, and it is the one where leaving it until October costs you both money and choice of appointment.
Is it too early to turn the heating on in September?
No, and there is a good reason to. Running it for twenty minutes now shows you which radiators are cold, whether the pump is noisy and whether the thermostat still works — while an engineer can still come out at short notice.
Do I legally have to do any of this as a homeowner?
In your own home, no. These are maintenance jobs rather than legal duties. If you let the property out, an annual Gas Safety Record and the smoke and carbon monoxide alarm rules do apply, and the requirements are set out on gov.uk.
What should I definitely not do myself?
Anything at height, anything on the gas side of a boiler, and anything involving the flue or the chimney. Gutters, roof checks and high paintwork are the classic ladder injuries, and gas work by an unregistered person is a criminal offence, not just unwise.
Researched by AI, edited and fact-checked by a human.
Editor & dev notes
Editor rewrite targets
•{'Verify every number and date before publish. Specifically': 'the 25 October 2026 clock change, the boiler service price range, the chimney sweep price range, and the Ofgem price cap change date at the start of October. Confirm each on the publish date and cite inline. Do not publish a figure that cannot be sourced on the day.'}
•Replace the generic "1950s semi in Berkshire" example with a real, named UK case study (with permission) where a September job prevented a winter failure — ideally a gutter or flat-roof example with a photograph.
•Inject a first-hand quote from the named RICS surveyor on which of these eleven jobs they most often see skipped, and what that costs by February. A second short quote from a Gas Safe engineer on September booking lead times would carry the heating section.
•Check the ventilation and condensation section against the current damp guide so the two posts agree on the advice and do not compete for the same query. Keep this post's treatment short and link out.
