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 AEG (FHP) 70W Motor for B9 Burner
AEG (FHP) 70W motor for Worcester Bosch B9 burner, compatible with multiple boil…
Worcester Bosch Greenstar 4000 System Diverter Valve Kit
Diverter valve kit for Worcester Bosch Greenstar 4000 system boilers
Ideal Parts User Control Kit
Boiler user control kit with digital display, knobs and screw
Glow-Worm Ultimate FF Gas Valve
Replacement full gas valve for multiple Glow-Worm boilers
Vaillant Complete Service Cock
Brass isolation valve for Vaillant ecoTEC boiler servicing
Baxi Ignitor
Baxi boiler igniter for select models; Gas Safe fitting required
Viessmann Controller - VBC112-A01.100
White PCB controller for Viessmann Vitodens 100 W WB1B boilers
Baxi Boiler Spare Part Microswitch with 3 Cables
Genuine Baxi microswitch with 3 cables, part 248207
Glow-Worm Heat Exchanger Door Assembly Ultracom 12-38 HXI SXI CXI
Heat exchanger door assembly for Glow-Worm Ultracom boilers
Glow-Worm Two Fuse Printed Circuit Board Ultimate Boilers
Two fuse printed circuit board for Glow-Worm Micron and Ultimate boilers.
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.











