A How To Guide on How To Repressurise a Potterton Boiler

If you’ve discovered your Potterton Boiler is displaying error code E119, the pressure in your unit is too low and needs to be repressurised.

Error code E119 only indicates that the system has low pressure and does not pinpoint the cause of the issue. While there are numerous reasons why a boiler can lose its pressure, it usually results from general use and is simple to fix.

Most homeowners will need to repressurise their boilers once a year or have a Gas Safe registered engineer do it during the annual service.

Now that we know what the error code means, how does one repressurise a Potterton boiler?

Step-By-Step Guide For Repressurising A Potterton Boiler

The normal pressure in a Potterton boiler is between 1 and 1.5 bar of pressure. It is also wise to ensure that when the boiler is operating, it doesn’t exceed a pressure of 2.5 bar.

As mentioned, almost all boilers need to be repressurised occasionally, but luckily, it is an easy task.

To start the repressurising process, you need to follow these steps:

Step 1: Switch Off The Heating System

Locate the fuse spur to turn off your boiler (it looks like a “big switch button”). The boiler may be connected to a standard home socket if this switch isn’t readily visible.

The specific setup can vary depending on the installer and how they connected the boiler to the power supply. If you can’t find an on/off switch, you can use the main switchboard to cut power to the entire house.

Let the heating system cool for several hours before proceeding, as it allows for a more accurate reading of the system’s pressure level. A warm system will increase the pressure reading.

Once you’re sure the power is off and the system has cooled, you can proceed to locate the system’s filling loop.

Step 2: Identify and Find The Filling Loop System

A filling loop system is used to top up the water levels in your boiler’s heating system or to connect your boiler to your home’s cold water mains.

There are two main types of filling loop systems:

• External filling loop: A detachable, braided silver hose.
• Internal filling loop: Built into the boiler, typically operated with a key or lever.

The filling loop is usually underneath the boiler on the right-hand side. Depending on the Potterton boiler model, it can be either system.

Step 3: Attaching the Filling Loop

Your Potterton filling loop pipe is usually stored under the unit to the right-hand side. A solid filling loop pipe with Potterton is considered the internal system, with the external being a braided silver hose.

Both filling loop systems must be removed when you’ve achieved your desired pressure.

Ensure both blue-handled isolating taps are in the OFF position. If unsure, the tap should be in the opposite direction of the pipe.

Remove the blanking caps and fit the temporary filling loop pipe, ensuring that flanged washers are securely attached to both ends of the pipe. The filling loop pipe will also have two wing nuts on the pipe that should only be tightened by hand.

Over-tightening this filling loop can cause issues in the future and even leaks.

Step 4: Open the Filling Loop Valves

Once the loop is attached, fully open the blue tap connected to the cold water mains pipe, and gently open the second to allow the water into the heating system.

While opening these taps, make sure to monitor the pressure gauge carefully.

Monitor the pressure gauge until the needle indicates a pressure between 1 and 2 bar.

Once the desired pressure is reached, turn both taps off.

You will now need to disconnect the filling loop system. Prepare a bucket and towels to catch any water that spills during this process.

Once completed, your repressurised Potterton boiler should be ready for use.

However, if you notice that you must repeat this process frequently, whether after a few hours, days, or every week, this could indicate a more serious pressure issue.

Common Reasons for Pressure Loss in Boilers

If your boiler continues to lose pressure, it’s likely due to one of the following common issues:

Improper DIY Maintenance

Bleeding your home’s radiators is a common homeowner task that removes air pockets.

Removing this built-up air improves efficiency, but excessive water release during the process can lower system pressure.

If you’ve recently bled your radiators, this might be the culprit.

Leaks in the Heating System

Another common issue with all boilers is leaks. Even a tiny leak can cause an E119 code to pop up.

Identifying hidden leaks behind walls, inside the boiler itself, or under the floors can be challenging, so it’s advisable to consult a professional if you suspect a leak.

Faulty Pressure Relief Valve

The pressure relief valve is a critical safety feature that releases excess pressure.

However, if it malfunctions, your pressure relief valve could open unnecessarily, causing a leak and lowering the system’s pressure.

It’s important to note that you should not attempt to fix this issue yourself. Only a Gas Safe registered engineer is qualified to handle such repairs safely.

Expansion Vessel Issues

The expansion vessel helps your boiler’s system maintain steady pressure.

If it’s damaged or malfunctioning, the system’s pressure will drop. Your boiler’s expansion vessel is vital to your unit, so only a Gas Safe-registered engineer can repair or replace it.

What should you do if you suspect your Potterton boiler has a serious problem?

What to Do If You Suspect a Serious Issue

If you believe your boiler’s pressure loss is due to a leak, faulty component, or another issue requiring professional attention, contact a qualified engineer immediately.

WarmZilla offers nationwide service and can send a Gas Safe registered engineer within 48 hours .

Contact one of our professional consultants today if you’d like to discuss your problem further.