Baxi is the UK’s bestselling budget combi boiler brand — a consistent presence in the entry-level new-build and replacement market for over three decades. The Baxi 600 and 800 ranges are among the most commonly installed combi boilers in UK housing stock, which means Baxi spares are in constant demand.
We stock genuine Baxi boiler spare parts for the 600, 800, and Platinum ranges, as well as older Duo, Combi Instant, and Solo models. PCBs, fans, pumps, diverter valves, and gas valves in stock for next day delivery.
Key Baxi Boiler Ranges
Baxi 600
The budget entry point — the Baxi 618 and 628 Combi are arguably the most commonly installed budget combis in UK social housing and buy-to-let properties. Outputs from 18kW to 28kW.
Baxi 800
The Baxi 800 Combi sits above the 600 in the range with higher efficiency, modulating capability, and a broader output range (24kW to 33kW).
Baxi Platinum
Baxi’s previous premium range, now replaced but widely installed from 2010 to 2018. Generally well-regarded by engineers.
Baxi Duo-Tec
A mid-range combi and system boiler range from the mid-2010s. The Duo-Tec 2 is still a common service target.
Most-Searched Baxi Parts
PCB: Baxi PCB failure is often indicated by fault code E168. PCBs are model-specific — Baxi 600 PCBs are not compatible with 800 or Platinum models.
Fan Motor: Baxi fan faults typically produce fault code E131 or E110 (depending on model generation).
Circulation Pump: A failed circulation pump prevents heat reaching the radiators.
Diverter Valve: Baxi combi diverter valve failure is a common fault. The diverter valve actuator motor is often the failing component rather than the valve body.
Gas Valve: E1 on Baxi indicates ignition failure. A failed gas valve is the root cause when electrode and lead are confirmed functional.
Baxi Fault Codes
E1 — Ignition Failure
The most common presenting fault on Baxi combis.
Diagnosis sequence:
- Check gas supply — are other gas appliances working?
- Check ignition electrode for damage, carbon fouling, or cracking
- Check ignition lead (HT cable) for damage or tracking
- Check gas valve operation — is gas reaching the burner?
- PCB ignition module if all above check out
Parts linked to E1: Ignition electrode, ignition lead, gas valve, PCB.
E119 — Low System Pressure
System pressure has dropped below the operating minimum. Re-pressurise via the filling loop to 1–1.5 bar. If pressure drops repeatedly, investigate expansion vessel and check for leaks.
Parts linked to E119: Expansion vessel, pressure gauge, PRV.
E168 — PCB Fault
The boiler’s PCB has detected an internal fault and locked out. E168 almost always indicates PCB failure.
Before replacing the PCB: Confirm the power supply to the boiler is stable and check the wiring harness for damage.
Parts linked to E168: PCB, wiring harness.
E110 — Overheating Lockout
Parts linked to E110: Circulation pump, heat exchanger, high-limit thermostat.
E131 — Fan Fault
Parts linked to E131: Fan motor assembly, air pressure switch.
Baxi and Potterton Cross-Reference
Baxi Group owns the Potterton brand, and there is significant parts commonality between Baxi and Potterton models from the same generation. Engineers working across both brands should confirm cross-reference availability with our helpline.
Compatible Baxi Models
Baxi 618, 624, 628 Combi; Baxi 800 Combi 24, 28, 33; Baxi Platinum Combi 24HE, 28HE, 33HE; Duo-Tec Combi 24, 28, 33, 40; Baxi EcoBlue Combi (current); Solo 2 RS (legacy); Combi Instant (legacy).
Need a Baxi Engineer Near You?
Our Recommended Installers have experience with the full Baxi range:
- HGB Heating Kent — Gas Safe engineers, Baxi specialists, Kent and Medway
- Boiler Sense — Certified boiler specialists, Kent and South East London