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Potterton Boiler Problems: Common faults (with costs to fix)

Problems with your Potterton? You're not the only one.

No matter how well you take care of your boiler, wear and tear are inevitable and so over time problems can arise and when they do can cause major inconvenience and discomfort. 

If your Potterton boiler is experiencing issues and you’ve no hot water, the good news is that many problems can be resolved without professional help. 

Potterton Boiler Pressure

In this guide, we will explore some of the most common Potterton boiler problems, along with their error codes and faults and explore some possible solutions. 

Need to know the cost of a new boiler, quick? Find out what replacement you need along with costs (takes 60 seconds).

Top 5 Potterton Boiler Problems 

Here are the top 5 most common Potterton boiler problems...

#1 Problem: Low Boiler Pressure (E119 Fault Code)

Potterton Low Boiler Pressure

Low boiler pressure is a very common Potterton boiler problem that occurs in all boilers and not just the Potterton models. If your Potterton boilers pressures drop too low, it will stop working and display the E119 error code. 

Low Boiler Pressure PottertonIf your boiler drops suddenly, it may be a sign of a significant problem, in which case you should consult a Gas Safe Engineer at the earliest convenience. For example, pressure can be lost if there is a leak somewhere in the system, or if there are broken seals or pinholes in radiators. 

However, it is quite common for boilers to lose pressure over time and is often easily fixed without professional help. 

The Solution

If your boiler has turned off – what is termed a “lockout” and is displaying the low-pressure error code, restarting the boiler will not resolve the issue. 

You will need to increase the pressure in the boiler, how exactly you do this varies from boiler to boiler, but you can find the exact instructions by referring to the user manual. 

Potterton Boiler Pressure

You can see the pressure level by looking at the pressure gauge if the needle is below 1 on the pressure gauge, this indicates the pressure is too low. Ideally, you want to top it up, until the needle sits within the green area, around the 1.5 mark. 

Potterton Boiler Filling Loop

Once the pressure is at the required level, you can then restart the boiler and it should resolve the issue. 

However, bear in mind that this is a quick fix and does not necessarily fix the root of the issue e.g. a hole somewhere in your heating system, responsible for the gradual loss of pressure. You will need to hire a registered Gas Safe Engineer to diagnose and repair the Potterton boiler problems. 

Think you may have an on-going issue with your boiler? Check our list of the top 10 boiler problems common in all types of boilers


Want an exact price on a new boiler? Use our boiler quote calculator (your fixed price will appear on screen).

#2 Problem: No Hot Water

No Hot Water Potterton

If you have no hot water coming from your Potterton boiler through your taps or shower, then there are many potential causes. With that said, one of the most common causes of no hot water is a faulty diverter valve. 

Diverter ValveThis is a mechanical component within the boiler, which controls the flow of hot water between your central heating system and water outlets. 

Over time diverter valves can become worn and begin to “stick” failing to open completely or only partially opening so that the flow of hot water is reduced. This can result in cold or lukewarm water. 

Learn all about combi boilers in our what is a combi boiler guide. 

The Solution

No hot water from your Potterton boiler is not necessarily caused by a faulty diverter valve, it could be caused by another problem such as a faulty Printed Circuit Board (PCB). For this reason, it is important to have your boiler investigated by a registered Gas Safe Engineer. 

Unfortunately, in many cases, a faulty diverter valve is an expensive part to replace and it makes more financial sense to replace your boiler

Read our in-depth article about faulty diverter valves

Is your boiler leaking or losing pressure? Use our quick and easy tool to get your fixed price boiler replacement

#3 Problem: Frozen Condensate Pipe (E133 Fault Code)

Potterton Frozen Condensate

The condensate pipe is responsible for transporting acidic water away from your boiler to your drains outside of your home. If the condensate pipe is frozen, your Potterton boiler will lockout and display the fault code E133

Potterton Frozen Condensate

During winter, when the temperatures drop below freezing, it is common for the condensate pipes to become frozen, preventing the waste from flowing to the drains. 

Curious to know which boiler brand performed worst? Find out in our report of the worst boilers

The Solution

Thaw Condensate PipeIf your condensate pipe is frozen, you can thaw out the condensate pipe quite easily. However, if you do not feel confident with this task a local Gas Safe Engineer will be more than happy to do it for you. 

To prevent this issue from reoccurring you can insulate the condensate pipe and instruct an engineer to re-locate the pipe to an area where it is less likely to fall below freezing point, like inside your house.

#4 Problem: Radiators Not Getting Hot

Radiators not getting hot (potterton)

If your radiators are not heating up evenly, or you notice that a radiator in a particular location is not getting warm or as warm as it should be, then you may have too much air in your heating system. 

Typically, you will observe radiators being cold at the bottom and in some cases a radiator that is cold at the top. This can be the result of “cold spots” forming where the air is slowing or preventing the flow of the hot water. 

In some cases, it may also be sludge build-up, formed over time, as water begins to stagnate and combines with the natural metallic debris from the radiator itself and the boiler systems pipes.

This sludge can cause blockages and prevent the hot water from flowing how it should, leading to cold spots in your radiator. 

The Solution

Bleed Radiator KeyIf you suspect too much air in your central heating system, then it may be time to bleed your radiators. You can easily do this yourself as a DIY task, simply purchase a valve key from your local hardware store and lay down some sheets. 

When your heating is switched off and cool, and you have prepared for the mess, with a bucket at the ready, it is time to release the excess air. Turn the valve using the bleed key and you should hear an audible hiss indicating air is being released. When the hissing stops you can close the valve and proceed to the next radiator. 

Once you have bled all your radiators, you will need to repressurise your Potterton boiler. If the issue continues, then the cold radiators may be caused by a different problem, such as sludge deposits. 

You can read our full articles about dealing with radiator sludge.

#5 Problem: Boiler Turning Off or Locking Out

Potterton Boiler Turning Off

If your boiler keeps “locking out” with no obvious cause or error code being displayed, then this could be caused by a variety of different issues, including a faulty heat exchanger, faulty thermostat, or a faulty PCB


Want an exact price on a new boiler? Use our boiler quote calculator (no personal details needed).

There are two major reasons why a boiler shuts off, either to prevent further damage to the boiler itself or to keep members of the household safe. Therefore, do not keep trying to restart the boiler before the exact problem has been investigated, diagnosed, and repaired. 

The Solution 

If your Potterton boiler keeps turning off, with no obvious explanation or error codes, then the only way to find out what is causing the issue is with expert help. A registered Gas Safe Engineer will be able to assist you.

Potterton boiler error codes

Fault Code Possible Cause
E09 Gas valve wiring fault
E10 Outdoor sensor error
E15 Gas valve connection fault
E20 Central heating thermistor sensor fault
E28 Flue thermistor fault
E40 Central heating return thermistor fault
E50 Hot water sensor fault
E53 Flue obstruction
E55 Calibration issue
E78 Water pressure sensor fault
E92 Combustion test alarm 
E109 Poor circulation
E110 Boiler overheat tripped
E117 System pressure too high
E118 System pressure low
E119 System pressure low
E125 Primary water circulation fault
E128 Loss of flame
E129 Loss of flame
E130 Flue thermostat sensor tripped (lockout)
E131 Flue overheat lockout
E133 Ignition fault
E135 Internal error
E151 PCB fault
E152 PCB fault
E154 Primary flow fault
E160 Fan fault
E161 Fan fault
E164 Hot water sensor error
E167 PCB fault
E168 PCB lockout
E193 Circulation issue
E270 Dry fire
E317 Wrong power supply
E321 Hot water thermistor fault
E384 Flame detected when gas valve off
E385 Low voltage

Should you replace your Potterton Boiler? 

Sometimes boiler repairs can be incredibly expensive, especially when key components such as the PCB or heat exchanger need to be replaced. The replacement parts, combined with the engineer’s labour costs can all add up, with some of these higher-end repair jobs costing around £500.

If you have an old boiler, no longer covered by a warranty and one which is inefficient in comparison to newer models, then you should seriously consider replacing your boiler. 


With a new boiler replacement, you'll get...

Long Warranty Period 

Installing a new, modern boiler means you are covered by a brand-new warranty (as long as 10 years in some cases), meaning that if any parts fail during that period, the boiler manufacturer will cover the costs and if necessary replace the boiler.

Boiler Warranty

If you decide to keep an old boiler with no warranty, then it is likely to continue to experience problems and you have got to consider how much that will cost you in the long term. 

Emergency call out charges, labour costs and replacement parts can easily end up costing you several hundreds of pounds each time. 


Need to know the cost of a new boiler, quick? Find out what replacement you need along with costs (takes 60 seconds).

Increased Energy Efficiency 

New, modern boilers are far more efficient than old boilers, this means they are better able to use the heat they produce and produce less waste. This means that you essentially use less energy and therefore save money on your heating bills. 

Energy Saving

For instance, if your boiler is an old G rated model and you replaced it with a modern A-rated boiler, you could expect to save as much as £315 a year on your energy bill. 

As you can see the potential savings you can make from replacing an old boiler, especially a broken one can make a lot of sense from a financial point of view. 

Check our new boiler costs guide and use our boiler size calculator if you want to get a better understanding of how our fixed price boiler quote tool works. 

Get a free boiler quote today 

At Heatable, we fit new boilers from as little as £1,545, all over the UK.

Use this clickable form to get a fixed price on the screen instantly.

What's more, as we've already covered, our boilers come with warranties which are up-to 10 years long. That's loooooong.

What's even more, we're able to offer low monthly payments with boiler finance, and even interest free options.

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