Potterton Boiler E133 Fault

Potterton Boiler E133 Fault Help Guide: What You Can Do

Last updated on June 10th, 2024

The Potterton boiler E133 fault code is shown on the display on the boiler when there is a problem and your Potterton boiler is not firing up and goes to lockout.

I have been carrying out boiler repairs full-time for over a decade and having fault codes on the screen when I arrive is very welcome.

Here I’ll show you how to deal with an E133 Potterton boiler fault based on my on-the-job experiences.

What Does E133 Mean on a Potterton Boiler?

Potterton boiler no hot water

The E133 boiler error code is also used on Main and Potterton boilers (Baxi owned). Potterton E133 and Main E133 are the same as the Baxi E133 fault.

The E133 Potterton fault code meaning according to the Potterton manual:

E133 indicates that the gas supply has been interrupted, ignition has failed or the flame has not been detected.

Here are some of the most common causes from my experiences:

  • Gas Supply Fault: A common cause of an E133 boiler fault is the boiler has been locked out due to not getting any gas. This can be checked quite easily without having to open up the boiler
  • Frozen Condensate Pipe: Another cause for an E133 fault could be a blocked or frozen condensate pipe. If it’s freezing cold weather and you have an external condensate pipe, then there is a good chance it has frozen causing your boiler to lockout
  • Faulty Boiler Parts: An E133 Potterton fault code could also mean that a part in the boiler is broken and needs to be replaced, but a lot of the time in my experience it is a gas supply issue

How to Fix a Potterton Boiler E133 Fault

To fix the E133 fault on your Potterton boiler, the first thing I would check is that the gas is turned on at the gas meters emergency control valve (ECV).

How to fix E133 on boiler
Emergency control valve turned on

Gas Supply Fault

If you have other gas appliances, like a gas hob or gas fire, then check to see if these are working to find out if you are getting gas at all.

Prepay gas meter: If you have a prepayment gas meter, then make sure you are in credit, as this is quite a common situation I come across.

Gas meter turned off
Gas meter turned off

Frozen Condensate Pipe

If it’s freezing outside, then having a frozen condensate pipe is possible. You can pour hot water on it to defrost the frozen condensate and reset the boiler.

frozen condensate pipe
Frozen condensate pipe

Faulty Boiler Parts

A gas supply problem or a frozen condensate pipe are the most common causes of a Potterton boiler E133 error but it could be caused by faulty boiler parts.

Here are some other potential causes:

  • Faulty gas valve: Might need a new one
  • Worn-out spark electrodes: Might need to be replaced
  • Faulty PCB (printed circuit board): The PCB is the brain of the boiler and might need to be replaced
Baxi boiler electrode
Potterton boiler electrode

How to Reset a Potterton Boiler

The first thing I would do on a Potterton boiler that is not working, no matter what fault code is showing, is to check the pressure and reset the boiler.

Knowing how to reset a Potterton boiler is the simplest way to get your boiler working again, as it might have just locked out.

Potterton Boiler Not Firing Up

Modern Potterton Boiler

To reset a modern Potterton boiler, you must find the reset button. This is a button that has ‘Reset’ on it. You have to press the button to reset the boiler.

Sometimes you have to hold it down for a few seconds, but on some Potterton boilers, it just needs to be pressed and released.

Baxi boiler reset button
Potterton boiler reset button

Older Potterton Boiler

If it’s an older Potterton boiler with a knob to turn the boiler on and off, then you will need to turn it fully anti-clockwise and hold it there (at R) until it resets.

How to reset a Baxi boiler
Potterton boiler reset knob on the left

Potterton E133 Won’t Reset

If your Potterton E133 won’t reset this means you have a problem that needs to be fixed before trying to reset it again.

When the ignition has gone to lockout it won’t reset until the cause of the E133 error is fixed.

If you have fixed a gas supply issue and it still won’t reset, this could mean there is air in the gas pipe.

You should try resetting it a few times to get the gas into the boiler and to get rid of the E133 error code.

Potterton Boiler Guides

Potterton boiler fault


Fixing an E133 Potterton fault code problem is usually done by fixing a gas supply issue. If you have a prepayment gas meter, make sure you put some money on and reset the boiler.

On a cold winter night, an E133 Potterton error is likely to be caused by a frozen condensate pipe. This is easily fixed by pouring hot water over the condensate pipe outside and resetting the boiler.

If you are sure you have gas and the condensate pipe isn’t frozen or blocked, then you should ring a local gas engineer as it could be a gas valve problem.

Feel free to ask me any questions in the comment section below and I’ll try my best to help.

Please share this post if you find it helpful.


How do you clear the fault code on a Potterton boiler?

To clear the fault code on a Potterton boiler, like Potterton E119 boiler fault and E133, you must reset the boiler.

If the fault code appears after resetting the boiler, you will need to find and repair the problem causing your Potterton boiler to lock out and show a fault code.

Why is my Potterton boiler not turning on?

If your Potterton boiler is not turning on at all, and nothing is on the display, then you probably have an electric supply issue.

You need to check the fused spur switch that should be next to the boiler. Make sure it is switched on and the 3 amp fuse is good.

It could also be that the circuit breaker at the main fuse board (consumer unit) has tripped, so you can check there also.


  • Steven Reid

    I am a full-time plumber and Gas Safe registered engineer. I incorporated Housewarm Ltd. in 2011 to provide heating and plumbing services to homes in Newcastle upon Tyne, England. I now blog about what I've learned over the years to help DIYers and plumbers.

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2 thoughts on “Potterton Boiler E133 Fault Help Guide: What You Can Do”

  1. Mohammed

    Good afternoon I would just like to know if you cover the Birmingham area Because I got a boiler issue ideal esprit eco boiler Sooner as I switch the hot water on it makes a rattling noise

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