Loss of pressure in your system. The system’s pressure is determined by the amount of water it contains.
It’s likely you’ll see the code and a flashing light on the front of your boiler. The appliance won’t work again until the pressure issue is fixed, and the boiler is reset.
Causes of the F1 Fault Code
In the simplest scenarios all that needs to be done, is to add water to the system via the filling loop.
However, if the system pressure is dropping, this indicates there could be a leak. This needs to be fixed before you increase your boiler’s pressure, otherwise your property/boiler could be subject to water damage.
Fixing the F1 Fault Code
Test the Pressure Sensor
If your boiler is sitting between 1-2 bar (1.5 bar is ideal), pressure isn’t the problem. However, that isn’t to say your boiler knows that the pressure is correct.
It’s the job of the water pressure sensor to tell the printed circuit board (PCB) whether the pressure is too high or low. If it’s not doing its job and giving the PCB false signals, the boiler won’t work, and the F1 fault code will be displayed.
So, your heating engineer will want to test the water pressure sensor; it might need replacing.
Lack of Pressure, or Pressure Loss?
If the pressure is lacking (i.e. sensor isn’t the issue), you’ll need to determine whether the problem is a lack of pressure, or loss of pressure.
A lack of pressure will require the boiler to be topped up with water via the filling loop (see how to increase boiler pressure below).
However, if the boiler pressure is consistently dropping, that’s a sign of a leak. You’ll want to get the leak fixed before topping up the boiler’s pressure, otherwise you could have expensive repair bills for internal boiler components due to water damage, or even plaster/floorboards if the leak is coming from pipework.
You’d expect a boiler to stay stable at 1.5 bar. Below 0.5 bar it’s going to stop working. So, is the boiler dropping pressure after it’s topped up?
Naturally, the next step is to find leaks. Even the smallest leak is going to mean water loss over time, and that means pressure loss too.
Your heating engineer will systematically check things such as:
Radiators and towel rails for pinholes
Copper pipework for pinholes or loose joints
The boiler’s pump and heat exchanger.
In most cases, the leak will be coming from one of the above. It needs to be fixed before increasing your boiler’s pressure. Call us on 07855382189