Complete guide to Assure, Titanium, Promax, Gold series fault codes with troubleshooting advice
Potterton boilers (part of Baxi group) share many error codes with Baxi boilers. Here is the complete list:
| Code | Meaning | Quick Fix | DIY? |
|---|---|---|---|
| E20 | NTC flow sensor fault | Reset boiler | No |
| E28 | Flue sensor fault | Reset boiler, check flue terminal is clear | No |
| E40 | NTC return sensor fault | Reset boiler | No |
| E50 | NTC DHW sensor fault | Reset boiler | No |
| E78 | Pressure sensor fault | Check pressure level, reset boiler | No |
| E109 | No circulation detected | Check pump operation, bleed radiators | Partial |
| E110 | Overheat protection activated | Let boiler cool, check radiators are on, bleed system | Partial |
| E117 | High water pressure | Bleed a radiator to release excess pressure | Partial |
| E118 | Water pressure too low | Top up pressure using filling loop to 1.0-1.5 bar | Yes |
| E119 | Low water pressure | Top up pressure using filling loop to 1.0-1.5 bar | Yes |
| E125 | Primary circulation fault | Check pressure, bleed radiators, check pump | Partial |
| E128 | Flame lost during operation | Check gas supply, thaw frozen condensate pipe | Partial |
| E131 | Flow temperature sensor fault | Reset boiler | No |
| E133 | Ignition failure - no flame detected | Check gas supply, thaw frozen condensate, reset boiler | Partial |
| E134 | Flame extinguished | Check gas supply, reset boiler | Partial |
| E151 | Internal fault | Reset boiler | No |
| E160 | Fan speed fault | Reset boiler, check flue is clear | No |
| E164 | No flame signal detected | Reset boiler, check gas supply | No |
| E168 | Ignition fault | Check gas supply, thaw condensate pipe, reset | Partial |
| E193 | System configuration fault | Reset boiler | No |
Our Gas Safe engineers service all Potterton models across Harrow and London.