Repair or replace your boiler?
Four questions about the boiler you already have, and a straight answer with the reasoning behind it. If repairing is the better move, the tool will say so.
- ✓Tells you to repair when repairing is right
- ✓Checks the warranty first, because that repair should be free
- ✓Explains what drove the answer, not just the verdict
- ✓Leaves a genuine judgement call as a judgement call
Repair it, or replace it?
Four questions about the boiler you have. No details needed, and you get the reasoning, not just a verdict.
How old is the boiler?
Still under warranty?Usually 5 to 10 years from installation.
What have you been quoted to fix it?
Breakdowns in the last 12 months?
Answer all four and the verdict appears here.
Check the warranty before anything else
This is the step people skip, and it is the one most likely to save you money. Boilers sold in the last decade routinely carry warranties of five, seven or ten years, and a fault inside that period should be fixed at the manufacturer's expense, parts and labour, by an engineer they approve.
Find the model and serial number on the front panel or the data plate behind it, call the manufacturer, and ask them to book it. Paying somebody else to fix a fault the warranty covers is money wasted twice over, because unauthorised work can invalidate what is left of the cover. Our boiler warranty guide covers what the longer warranties actually require of you.
What actually decides it
Four things, and the price of the repair is only one of them. Taken together they are usually enough to see the answer without an engineer in the room.
Age
Under eight years and a boiler normally has plenty left. Past twelve the calculation inverts, because parts get scarcer and the next fault is closer.
The size of the bill
Once a repair passes roughly half the cost of a replacement, the money is better spent on the new boiler, which arrives with a warranty the repair does not.
How often it fails
One breakdown is bad luck. Three in a year is a pattern, and each call-out costs money whether or not it fixes anything for long.
What else is close to going
The engineer who quoted the repair can tell you what is likely to fail next. That answer moves the decision more than the price does.
If you decide to repair
Repairing is frequently the right answer, and this page is not trying to talk you out of it. A few things make the repair go further. Get the annual service booked while an engineer is already coming, because a serviced boiler lasts longer and keeps whatever warranty remains intact. Ask for the old part back, or at least to be shown it. And get the diagnosis in writing, so that if the same fault returns you have a record rather than an argument.
If the answer comes back as replace, our boiler size calculator will tell you what output to ask for, and our guide to comparing quotes sets out what each one should itemise so three prices can be read side by side.
Frequently asked questions
How long should a boiler last?
A well maintained condensing boiler typically lasts ten to fifteen years, and an annual service is the single biggest influence on where in that range yours lands. Past fifteen years you are usually running on borrowed time: parts get harder to source, efficiency has fallen behind what a new unit would deliver, and the case for spending several hundred pounds on a repair gets steadily weaker.
When is a boiler repair not worth it?
A useful rule of thumb is that once a repair costs more than about half of a replacement, the money is better put towards the new boiler, because the repair buys you no warranty and no guarantee the next fault is far away. Age and frequency matter just as much: three failures in a year on a twelve year old boiler is a pattern, not bad luck.
My boiler is under warranty. Who pays for the repair?
The manufacturer, provided the boiler was registered and has been serviced annually with the service recorded. Call the manufacturer directly with the model and serial number from the front panel and ask them to book an approved engineer. Paying a third party to fix a fault the warranty covers can also invalidate the rest of the cover, so it is worth the phone call first.
Does a missed service void my boiler warranty?
Not usually outright, but it can lose you cover for any fault that service would have picked up, which tends to be exactly the fault you are claiming for. If you have missed one, book a service before you make a claim rather than after.
Should I replace a working boiler just to save on bills?
Rarely on its own. Replacing an old non-condensing boiler with a modern condensing one does cut gas use meaningfully, but the saving takes years to cover the cost of the installation, so it is a stronger argument when the boiler is already unreliable or has just presented you with a large repair bill. If the boiler is working well and is under about ten years old, servicing it is usually the better spend.
What should I ask the engineer who quoted the repair?
Three things. Whether this fault is isolated or a symptom of something larger, what else is likely to fail within two years given the boiler's age and condition, and whether the parts are still readily available for that model. Those answers move the decision far more than the price of the repair on its own.