Boiler spares are picked by appliance match first, then by the fault you’re chasing. If you need boiler parts for a straight swap, stick to the exact component and layout the boiler calls for. For boiler service parts or boiler repair parts, a kit or seal set can be the cleaner buy than piecing together individual boiler components. The usual snag is assuming one valve, sensor or seal will fit across similar models.
Worcester Bosch Control Box UBA3
Worcester Bosch UBA3 control box for boiler user interface and programming
Parts 8656807 Cartridge 3 Way Valve
Replacement three-way valve cartridge for Baxi combi boilers
HAM Service Kit
Hamworthy gasket service kit for ModuMax boilers, contains seals to prevent leak…
Worcester Bosch Heat Exchanger Bare Including New Sump
Replacement heat exchanger with sump for Worcester Bosch 18Ri LPG boiler
Glow-Worm Domestic Hot Water Sensor (SXI, CXI & CI)
Domestic hot water sensor for Glow-worm SXI, CXI and CI boilers
Baxi 105E Fan Assembly
Baxi fan assembly for 105E, Combi, System and Performa boilers
Worcester Heat Exchanger Series Cleaning Set - 77190019960
Cleaning set for Worcester HE Series boilers
Vaillant Non Return Valve - 15mm
15mm non-return valve for Vaillant ecoTEC plus boilers
Vaillant Fan
Vaillant fan (0020216847) for multiple appliances
Ideal Parts Fan Assembly Super Ser4 Spares Only
Fan assembly for Ideal Concord Super Series 4 boiler, 230V, part 170950
Start with the appliance match and the fault, then check the system and flue before you look at anything else. That’s where most wrong orders happen with boiler spares, not on the part itself. Condensing is the baseline on most modern jobs, so the real split is usually system, combi or regular, plus whether you’re dealing with gas or oil. Filtration matters where the system has been carrying debris. Gas Safe fitting responsibility can change what you’re allowed to supply. In practice, boiler parts that look close enough often aren’t once the model and layout are checked.
Some boiler spares are bought as individual boiler parts when you know exactly what’s failed. That keeps the job tight and avoids paying for bits you won’t use.
Boiler service parts suit routine maintenance. They’re usually the wear items you expect to change more than once.
Boiler repair parts are the better call when you’re chasing a specific fault and need the exact component back in. Boiler replacement parts make sense where the original has gone beyond a sensible repair, but you lose the speed of a simple swap if the appliance is awkward to strip.
On the Central Heating side, the usual mistake is buying by description alone instead of by the actual layout of the boiler components.
Exact-match boiler parts are the right call when you know the appliance and the fault. You avoid fit issues and function mismatches. The trade-off is usually price and lead time.
Universal or mixed boiler components can suit older repairs, but they can cost you time when the original setup is awkward. For parts around the job rather than inside it, Central Heating Accessories is the next stop. If the fault sits in the zone control rather than the boiler itself, Motorised Valves is where you’d go next.
Once you’ve got the main unit sorted, the next call is what else needs to sit around it on the job. With boiler spares, that usually means the parts that finish the repair properly - controls, filters, and the right boiler accessories - rather than the failed part on its own.
A lot of call-backs come from missing the small item that should’ve been changed at the same time. The other common issue is fitting a part that’s right in principle but wrong for the appliance family. If you’re also ordering from central heating accessories or motorised valves, keep the system layout in mind and don’t mix in parts that belong to a different setup.











