Fix it yourself! Common errors, codes, and fixes for Potterton boilers
Potterton boiler faults are common across Kent — from Swanley and Dartford to Orpington and Bexley. While Potterton models are generally reliable, error codes and lockouts do crop up. This guide covers quick checks and safe fixes you can try before booking a Gas Safe engineer.
1) Potterton Boiler Faults: Low Pressure (E119)
Symptoms: No heating or hot water; display shows E119 / E118 (system pressure too low).
Fix: Check the pressure gauge. If it’s below 1.0 bar (cold), top up to ~1.3–1.5 bar using the filling loop beneath the boiler. If pressure keeps dropping, you likely have a system leak — arrange leak detection and repair.
2) No Hot Water (Radiators OK)
Symptoms: Heating works but taps/shower stay cold; hot water demand feels intermittent.
Fix: Often a sticking diverter valve or sensor issue. A service can free/replace the valve and recalibrate controls. Book a heating system check if it’s recurring.
3) Frozen Condensate Pipe (E133)
Symptoms: Lockout with E133 (ignition fault) during freezing weather; gurgling on startup.
Fix: The outdoor condensate pipe may be frozen. Pour warm (not boiling) water over the external run and joints, then reset the boiler. To prevent repeat faults, consider lagging the pipe and increasing fall to the drain.
4) Other Common Potterton Boiler Error Codes
| Error code | Likely cause |
|---|---|
| E09 | Gas valve wiring fault — engineer diagnosis required |
| E20 | Central heating sensor (NTC) fault |
| E50 | Hot water sensor (NTC) fault |
| E118 | System pressure too low |
| E133 | Ignition/lockout — often condensate or gas supply related |
Quick Potterton Boiler Checks Before You Call
- Programmer & thermostat: Confirm schedules are “ON,” time is correct, and setpoint is above room temperature.
- System reset: Power-cycle the boiler per the manual (never repeatedly reset a lockout without finding the cause).
- Bleed radiators: Trapped air can trip sensors and reduce flow; recheck pressure after bleeding.
- Gas supply: If other gas appliances fail, contact your supplier. For appliance faults, use a Gas Safe engineer.
When to Stop DIY and Call a Gas Safe Engineer
Smell of gas, repeat E133 lockouts, electrical faults, or persistent Potterton boiler faults (E09/E20/E50) all need professional attention. We’ll diagnose sensors, pumps, PCB and valve wiring, and restore safe operation.
Trusted Local Help Across Kent
From Dartford, Swanley, Eynsford, Newbarn, Hartley and Farningham to Hextable, West Kingsdown, Crockenhill, Wilmington, Orpington and Bexley, DAKS Plumbing offers fast callouts for boiler & heating, general plumbing, and leak detection.
Safety & Servicing
Annual servicing reduces Potterton boiler faults, improves efficiency and keeps warranties valid. Always use a registered engineer — check the Gas Safe Register.
Need Professional Help?
If you’re struggling to fix your Potterton boiler, DAKS Plumbing is here to help. We provide plumbing services, leak detection, and heating solutions across Kent.