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Potterton Boiler E270 Fault Code


The Potterton fault code E270 water pressure in the heating system Q & A or require an engineer for an emergency boiler repair.


The Potterton Boiler Fault Code E270 Error Common Q & A


Just below, we have a list of common questions relating to the E270 fault code on the Potterton boiler.

Potterton Boiler E270 Fault Code
  • What does the E270 fault code mean on my Potterton boiler?
  • What can cause the E270 fault code to be displayed on my Potterton boiler?
  • Can I fix the problem on a DIY basis?
  • What pressure should my boiler be?
  • How do I top up my boiler to clear the E270 fault code?
  • I’ve topped up my boiler to over 1.5 bar by accident, what can I do??
  • If my boiler is showing the E270 fault code, should I turn off my appliance?
  • How will I know if there’s a leak in my central heating system?
  • I can’t find the leak in my heating system; will my heating engineer be able to fix the problem?
  • What parts can leak in my boiler?
  • Why would the heat exchanger start leaking, and can it be fixed?
  • Why would the pump start leaking, and can it be fixed?
  • If my boiler has a leak, will it cause damage to other components?
  • What does the expansion vessel and PRV have to do with the E270 fault code?
  • Is it worth considering a new boiler?

What does the E270 fault code mean on my Potterton boiler


If your Potterton boiler is displaying the E270 fault code, there’s a problem with the water pressure. According to Potterton, this leads to a circulation fault, also known as a “dry fire”.

Your boiler needs a certain level of pressure to operate at its optimum. And, this pressure is determined by the amount of water in the heating system. Parts like the heat exchanger and pump will be working overtime, because there’s not enough water, or pressure, in the boiler.

What can cause the E270 fault code to be displayed on my Potterton boiler


There are a few scenarios that can lead to the E270 fault code being displayed, including:

  • The boiler wasn’t topped up correctly by the last engineer
  • There’s a leak in the heating system
  • The pressure release valve (PRV) and/or expansion vessel are faulty

Can I fix the problem on a DIY basis


The only time you should attempt to fix this problem on a DIY basis is if you’ve just moved into your property, and the boiler pressure wasn’t set correctly to start with. If you suspect a leak, you shouldn’t top up the boiler, until the leak has been found and fixed.

What pressure should my boiler be


If your boiler is showing a low pressure or circulation fault such as the E270, it’s likely the pressure has dropped below 0.6 bar. A modern boiler will usually lock out if the pressure drops below 0.6 bar, or if it goes above 3 bar.

Most modern boilers work at their best when set to around 1.3 bar (always check your owner’s manual).

How do I top up my boiler to clear the E270 fault code


To top up your boiler, you’ll need to locate the external filling loop. The external filling loop is a braided hose that’s usually located below the casing on your boiler.

On the filling loop, you’ll notice a fill valve. You can slowly open this valve to let water (and therefore, pressure), into the boiler.

Be careful not to only overfill the boiler. A boiler working at a pressure above 1.5 bar is going to put excess strain on components. That’s going to mean that they wear out prematurely, and that’s also going to increase the chance of more leaks occurring.

I’ve topped up my boiler to over 1.5 bar by accident, what can I do?


First, don’t use your boiler for heating or hot water. If you do, the pressure will rise slightly as the water rises, and strain all boiler components.

You can either use the drain cock in your property, or bleed valves on radiators to remove water (and therefore, pressure). You’ll need to have someone checking the boiler’s pressure gauge whilst you slowly open the valve.

Remember, you’ll be removing water from the system. So, you’ll need towels and containers to stop the water from damaging flooring and carpets.

There’s a chance you’ll hear a hissing noise (when bleeding water from radiators) first, this is air escaping and nothing to worry about. Once the hissing stops, water will dribble out of the radiator.

Make sure you fully close the valve, wipe the area dry, and check the bleed valve you opened after the heating is up to temperature, to ensure it’s not leaking.

If my boiler is showing the E270 fault code, should I turn off my appliance


A boiler showing the E270 is rarely dangerous. However, it’s most likely that there’s a leak in the heating system. By using your boiler for hot water or heating, you’ll be increasing the pressure in the system. Now, this is only a slight increase, but that can help to force water via the point of the leak.

And, any leaking water is likely to cause damage. This might be damage to plaster if the leak is external to the boiler, or damage to internal boiler components.

How will I know if there’s a leak in my central heating system


Leaks can come from any part in your central heating system. And, some leaks are easier to spot than others.

The first step is to do a visual inspection. Look around your property for any sign of damp patches on walls, ceilings and floors.

If you can’t see any damp patches, look at individual heating parts such as:

  • Towel rails
  • Radiator valves
  • Radiators
  • Joints on pipework
  • Your boiler

I can’t find the leak in my heating system; will my heating engineer be able to fix the problem


There’s a leak somewhere, and your heating engineer will be able to find it. Sometimes leaks are miniscule, and that makes them incredibly difficult to find.

For instance, a radiator valve could have been knocked and the copper olive inside dislodged. This would cause a small amount of weeping that’s barely noticeable. In this case, draining the system, refitting the valve with fresh PTFE and a new copper olive would solve the problem.

What parts can leak in my boiler


There are two parts in your boiler that are well known for developing leaks; the heat exchanger and the pump.

Why would the heat exchanger start leaking, and can it be fixed


The most common cause of a heat exchanger leak is limescale build-up, that leads to a crack. Heat exchanger plates are extremely fragile, and when limescale (minerals from water) settle on the plate, they burn hotter than they should. This weakens the plate, cracks it, and that causes a leak.

Although most boiler components can be repaired, in this case, you’ll need a replacement heat exchanger. Unfortunately, heat exchangers are incredibly expensive. You should expect to pay somewhere in the region of £450 including parts and labour.

Why would the pump start leaking, and can it be fixed


We find the most common cause of a heating pump leak, is blown seals. These seals are durable, but they do eventually degrade. And, there can be catalysts that make them fail, such as a boiler pressure that’s too high.

If the pump is in good condition, your boiler engineer will suggest fitting a service kit. This will include new seals and will stop the pump leaking. After topping up the boiler, the E270 error will be cleared.

However, if the pump’s overall condition is poor, it makes little sense investing cash in repairing the component. Instead, it will be cost efficient in the long-term, to have a new one fitted. You should expect to pay £250 for a replacement pump, including parts and labour.

If my boiler has a leak, will it cause damage to other components


The quicker a leak is found and fixed on your boiler, the better. Older boiler’s electrical components aren’t sealed particularly well. And, that means that when a leak occurs, it can cause a whole host of damage.

Even when water doesn’t drip directly onto electrical components, condensation builds-up thanks to the internal heat of the boiler. And, some of these components (such as the PCB), can cost upwards of £450 to replace.

So, if you suspect a leak, you should get in touch with a boiler engineer as soon as possible, and refrain from using heating/hot water where possible.

What does the expansion vessel and PRV have to do with the E270 fault code


The expansion vessel and pressure release valve help to relieve excess pressure when needed; usually when the boiler is working near it’s maximum output. But, these parts are known to fail.

When they do, they can relieve pressure, even when they don’t need to. If this is the case, they could easily drop the pressure on your boiler below the critical 0.6 bar and cause the appliance to lockout and display the E270 fault code.

So, if leaks can’t be found, your boiler repair engineer will look at the PRV and expansion vessel for faults.

Is it worth considering a new boiler


This really depends on the age and condition of your current boiler. We tend to find that when repair bills exceed £500 and a boiler is out of warranty, it makes sense to at least investigate new boiler quotes.

However, if your boiler repair bill is heading towards £1,000, it almost always makes sense to get a boiler that’s more efficient, complete with a parts and labour warranty.

Other Potterton boiler issues


For more boiler issues regarding the Potterton Boiler then please visit the Potterton Boiler Problems And Cures page.