Why is my boiler flashing E1 then 19?

E119 is the standard low-pressure fault for Baxi, Potterton, and some other generic Baxi boilers like Mains.

There is a pressure sensor inside the boiler. When the water pressure drops to roughly 0.5 bar the pressure sensor tells the boiler to lock out and display the E1 19 fault code.

What can I do to fix an E119 fault?

The fault is generated when the pressure goes below 0.5 bar. Turning the reset switch will not clear an E119 code. The only way to clear an E119 fault code is to increase the pressure.  

What causes a pressure drop?

An E119 fault is caused by the water pressure in the boiler, radiators and pipework dropping below 0.5 bar.

The pressure drop is caused by:

• A fault inside the boiler.
• A leak on a radiator.
• A leak on a radiator lockshield valve.
• A leak on a thermostatic radiator valve.
• A leak on the central heating pipework
• Bleeding radiators without replacing the water.

Where should I look for leaks?

Check around and under the boiler for leaks. Even if no water is showing it may still be the boiler

Go to each radiator and check them for leaks along with any pipework running to them.

If you’ve bled air from radiators the air has to be replaced by water from the filling loop.

Check the metal pipe coming from your boiler for leaks, especially when the radiators are hot.

When the radiators are hot is the pressure rising above 3 bar? You may have an expansion vessel problem.

How do I clear my E119 fault?

To increase the pressure you use the filling loop. There will be either an external filling loop or a built-in version.  

You are trying to increase the pressure to somewhere between 1 and 1.5 bar.

There are several types of filling loops. This depends on the model of boiler you have, the way it was installed and it’s age.

Click here to jump to our helpful guide on filling loops.

My pressure is above 1bar but I still have an E119 fault

If the pressure gauge is above 1 bar but you still have an E119 there are two possible causes:

1. The pressure is actually above 1 bar and the pressure sensor is faulty.
2. The pressure is actually below 1 bar and the pressure gauge is faulty.

Both of these faults will need a visit from a gas safe heating engineer.