Boiler part information, kept apart from the business of selling parts.
A fault code here tells you what's likely wrong and which part to look for, then leaves the buying to you and whichever supplier suits you. Nothing on this site is written to steer you toward one over another, because it doesn't sell parts itself.
Fault codes, parts and suppliers
A fault code on a boiler display tells you that something has failed, but on its own it rarely tells you which part is responsible or whether you're allowed to fit the replacement yourself. That gap, between the code on the screen and the part you actually need to order, is what this site works through.
Reading the code
Enter a fault code together with the boiler's make and model and you get back what the code means, the component most likely at fault, and the part number to look for. The same digits can point to a different fault on a different model or firmware version, so the answer is tied to the specific range it applies to.
Checking the part fits
A part number found online does not always match the boiler standing in front of you, particularly where a connector or fitting has changed between production runs. The compatibility data here comes from manufacturer service manuals and is dated as such, but it can still be wrong for an appliance it wasn't written to cover, which is why it's worth checking the part against the physical label before fitting it.
Working out who does the job
Some boiler repairs are within reach for a competent homeowner. Others are restricted by law to a Gas Safe registered engineer, and where that line falls is stated for each component.
Finding somewhere to buy the part
Once the part is identified, the supplier directory lists UK retailers who stock it. Each listing is checked against stock, dispatch and returns before it appears, and dated so you know how recent that check is.
Fault code lookup
Enter a code with your boiler's make and model to see what it means and which part is most likely at fault.
Part identification
Get the manufacturer part number for the failed component.
Compatibility check
Confirm whether a part matches your specific model before you order it.
Verified suppliers
Find UK retailers stocking the part, each checked and dated.
Where the part numbers and fault codes come from
A fault code only means something if it is tied to the exact part it should be. Boiler manufacturers change components across a production run, so the same display code can point to a different sensor or valve depending on when the appliance was built, and that is the problem this section is really about.
Manufacturer service manuals as the starting point
Part numbers and fault code meanings are drawn from manufacturer service manuals, the documents engineers already use on site. Where a manufacturer publishes a compatible or superseded part number alongside the original, that is noted too, because the original code is sometimes withdrawn long before the boiler itself is.
Naming the range a code applies to
A fault code page states the model range and, where the manual distinguishes them, the serial or firmware range it applies to. This matters because manufacturers revise service manuals as production changes, and a code that means one thing on an early unit can mean something else once a component is redesigned.
When the manual does not settle it
Manuals are not always complete, and a variant sometimes falls between two documented ranges. Where that happens, the page says so, and points the reader toward checking the label on the physical part or toward a Gas Safe registered engineer for anything that touches gas-carrying components.
Any compatibility data built from this material can still be wrong for a specific unit, particularly where a boiler has been repaired or modified before. Checking the part number against the label fitted to the appliance itself remains the only way to be sure before ordering.
How we verify suppliers
Ordering a part from a supplier you've never used before is a bit of a leap. You're trusting that they actually hold the stock, that it will arrive when they say it will, and that they'll take it back without a fight if it turns out to be the wrong one. None of that shows up on a supplier's own product page, so it's checked separately before that supplier appears anywhere on this site, and the check is dated so you can see how current it is.
What gets checked
Each entry notes what was looked at. That includes whether the part is actually in stock, how quickly a supplier tends to dispatch once an order is placed, and what their returns policy actually says if the part doesn't fit or arrives wrong.
- Stock availability for the part categories the supplier covers
- Dispatch speed once an order is placed
- Returns policy, including what happens if the wrong part turns up
How often a listing is checked
A supplier's stock levels and dispatch times can shift within weeks, so a listing that hasn't been looked at in a while stops being useful even if nothing else about it has changed. A last-checked date sits on every entry for that reason, and a supplier that falls too far out of date drops off the directory.
How the rating is built
Where a supplier carries a rating, it comes from data on actual purchases. The sample size behind the rating is shown alongside it, so a rating built from a handful of purchases can be weighed differently from one built on a lot more.
Some listings are sponsored placements. Where that's the case, it's marked as such next to the entry, separately from the rating itself.
When a listing comes down
A supplier is removed when the last check falls out of date, when stock or dispatch claims stop matching what's checked, or when a returns policy changes for the worse without notice. A verified date and a rating are a starting point for deciding where to buy, not a guarantee of what you'll get on the day you order, since stock, dispatch times and policies can all change between one check and the next.
How BoilerPart is funded
Running a free site like this still costs money to keep going, and that has to come from somewhere other than the reader's pocket.
Two things pay for it. When a fault code page or a directory entry sends you on to a parts retailer, that link is often an affiliate one, meaning a purchase you go on to make can earn a small commission. Separately, some entries in the supplier directory are sponsored, paid for by the supplier that appears there.
What that does and doesn't change
A sponsored listing doesn't buy its way past the checks a supplier still has to meet, and an affiliate link doesn't decide which component a fault code points to. Where a link is affiliate, or a listing is sponsored, that's marked next to the thing itself rather than tucked away somewhere you'd need to go looking for it.
The site stocks no parts and sells nothing directly, so none of this changes the price you pay a retailer for a part. If anything about how a listing ended up on the page isn't clear, you're welcome to get in touch.