Potterton is part of the same company as Baxi, and Potterton Assure boilers appear in Baxi's own fault code table. Codes show as an E and three numbers, and E133 often alternates as E1 then 33.
E133 is the most common Potterton code. Potterton says it is the code you'll see when the condensate pipe has frozen.
| Code | What it means | Models | Can you fix it? |
|---|---|---|---|
| E133 | Gas supply or ignition fault, often a frozen condensate pipe. | Potterton Assure (in Baxi's fault table) | Checks first |
| E118 | Low water pressure (below 0.5 bar). | Potterton Assure (in Baxi's fault table) | Usually yes |
| E110 | Overheat: the safety thermostat has tripped. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E125 | Water circulation fault. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E160 | Fan fault. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E09 | Gas valve connection fault. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E10 | External probe fault. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E12 | Differential water flow switch fault (still open). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E13 | Differential water flow switch fault (still closed). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E15 | Gas valve command fault. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E20 | Central heating temperature sensor fault: short circuit or open circuit. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E28 | Flue temperature sensor fault: short circuit or open circuit. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E40 | Return central heating temperature sensor fault: short circuit or open circuit. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E50 | Hot water temperature sensor fault (tank boiler): short circuit or open circuit. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E83 | No communication. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E84 | No communication. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E85 | No communication. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E86 | No communication. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E87 | No communication. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E103 | Safety Assist battery is exhausted. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E104 | Faulty Safety Assist PCB. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E107 | PCBs not synchronised. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E109 | Precirculation alarm. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E128 | Safety error for frequent loss of flame. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E129 | Safety error for frequent loss of flame with maximum correction during ignition. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E130 | Flue thermostat sensor tripped (lockout). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E134 | Gas valve open for too long without gas. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E135 | Internal error. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E154 | Plausibility test (flow/return). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E270 | Dry fire. | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E317 | Wrong power supply electrical frequency (Hz) (also shown as 162). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E321 | Hot water temperature sensor fault (also shown as 163). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E384 | False flame (parasitic flame) (also shown as 164). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E385 | Under voltage (also shown as 165). | Potterton Assure (in Baxi's fault table) | No, engineer only |
| E430 | Water pressure temporary fault or test failed (also shown as 166). | Potterton Assure (in Baxi's fault table) | No, engineer only |