Potterton boilers covered
Potterton is one of the oldest boiler names in the UK and is now part of the Baxi group, so its boilers are made and supported by Baxi Heating UK. Many Potterton models share parts, controls and fault codes with Baxi boilers of the same era, which is why you will see links to our Baxi fault code pages throughout this section. The ranges we get asked about most are:
- Potterton Assure, the current range, available as combi, system and heat-only boilers.
- Potterton Promax, a long-running range that includes the Promax Combi HE Plus and Promax System HE Plus.
- Potterton Titanium and Potterton Gold, earlier high-efficiency combis that are still common in UK homes.
- Potterton Performa, an older range. Some Performa models report faults differently, so check the manual for your exact boiler.
How fault codes appear on a Potterton boiler
The way a code shows depends on the age of the boiler. On Promax, Titanium and Gold models the code starts with the letter E. Three-digit codes are too long for the display, so they alternate: E133, for example, shows as "E1" and then "33". On Assure boilers the display shows the number, such as 133, alongside a symbol. An R symbol means you can try a reset. A spanner symbol means the fault cannot be reset by the user and needs an engineer.
Write the code down exactly as it appears. It saves time when you call an engineer or Baxi customer support.
How to reset a Potterton boiler safely
The reset method differs between ranges, so check your user guide first:
- Assure: press the Reset button for about one second. The manual notes that holding it for more than two seconds will not reset the boiler.
- Promax, Titanium and Gold: turn the selector switch to the reset position and hold it for about five seconds before releasing.
Deal with the likely cause before you reset, such as low pressure or a gas supply problem. Stop after two or three attempts. A code that keeps coming back points to a fault that resetting will not fix.
Checking the pressure gauge
Every Potterton sealed system boiler has a pressure gauge on or under the front panel. Potterton manuals give a normal operating range of roughly 1 to 2 bar (up to 2.5 bar on some older models), and the boiler stops below about 0.5 bar. With the heating cold, a reading of 1 to 1.5 bar is a good target. On older models low pressure shows as E119, while Assure boilers use code 118 instead. Our guide on how to repressurise a boiler explains how to top up with the filling loop.
Common winter faults
Potterton condensing boilers drain acidic water through a plastic condensate pipe, often to an outside drain. In a hard frost it can freeze, the water backs up and the boiler locks out, very often with E133. Thawing the pipe with warm (not boiling) water is a safe job for a homeowner, and our frozen condensate pipe guide shows how.
Potterton fault codes we cover
- E133: interruption of gas supply or flame failure
- E119: water pressure switch not operated (low pressure)
- E110: safety thermostat operated (overheat)
When to call a Gas Safe engineer
If you smell gas, turn off the supply at the meter if it is safe to do so, open doors and windows and call the National Gas Emergency Service on 0800 111 999. Never remove the boiler casing. The gas valve, fan, pump, sensors and circuit board must only be handled by a Gas Safe registered engineer. If your boiler is still under warranty, contact Baxi first, as it looks after Potterton warranty repairs.