Potterton Common Fault and Error codes

Potterton Common Fault and Error codes

The fault and error codes of Potterton boilers, like those from other manufacturers, help diagnose problems in the boiler. These codes make it easier for homeowners and technicians to pinpoint specific issues, accelerating problem-solving as well as repairs. So, here are some of the most common Potterton boiler fault and error codes and their general meanings:
E110: Overheat – The maximum safe temperature of the boiler’s water is exceeded causing this problem. This may be due to a faulty thermostat or water flow restrictions that overheat the pump.

E119: Low Water Pressure – It means that there is little enough pressure in the system to cause a drop below what is required normally when leaks or natural pressure loss occur.

E125: Circulation Fault – This suggests that there is no water circulation through the system caused by a faulty pump or blocked pipes restricting it.

E133: Ignition Failure—This code occurs if the boiler does not ignite because of gas flow problems, ignition electrode faults or flue blockage.

E160: Fan Fault – A fan fault indicates that something has gone wrong with an important part of your heating service where exhaust gases are expelled out and fresh air drawn in for burning.

E20: Central Heating Thermistor Sensor Fault – It points towards a problem with central heating water temperature measuring probe known as thermistor.

E28: Flue Thermistor Fault – Error E28 stands for flue thermistor trouble which measures flue gases temperature.

E40: Central Heating (CH) Return Thermistor Fault – It is indicative of an issue regarding return water temperature sensor located on central heating return pipe.

E78: Water Pressure Sensor Fault – Probably there is something wrong with the component responsible for measuring pressure within your system now.

E83, E84, E85: PCB Fault – These entail various failures associated with Printed Circuit Board (PCB), which controls all operations performed by this device.

Troubleshooting and Resolution

E110 (Overheat) and E125 (Circulation Fault): Look for obstructions, verify the pump is in good condition, and test the thermostat.

E119 (Low Water Pressure): Re-pressurize your system if needed and investigate possible leaks.

E133 (Ignition Failure): Check for gas supply to boiler; examine ignition electrodes’ state; make sure there is nothing that blocks the flue.

E160 (Fan Fault): Start by inspecting if the fan rotates freely and then ensure there are no electrical problems or objects in its path hindering performance.

E20, E28, E40 (Thermistor Faults): These ought first of all to be assessed for any damage or poor connections as well as replaced where necessary.

E78 (Water Pressure Sensor Fault): Confirm that water pressure sensor has not been damaged with no readings that are wrong before replacing it.

E83, E84, E85 (PCB Fault): Because of PCB complexity it’s usually left to professionals to diagnose such problems properly.


Potterton boiler fault codes are very useful when it comes to identifying heating system issues. Though some problems can be fixed through basic troubleshooting techniques, other will require the intervention of specialists due to their complexity or need for professional expertise and equipment. Regular maintenance from a qualified engineer can help avoid many common faults while also ensuring efficient and safe operation of the boiler.