Combi Boiler Pressure too High

Myser

If your filling loop arrangement has two similar valves with a flexi pipe in between, the off position is usually when the lever on both valves is horizontal to the body.

You can confirm this the next time you fill the system - note the position you have to turn both valves to allow water through and to shut off the water.

Strictly speaking, the filling loop (flexi pipe) should be removed once filling is complete however, not many people do that!

pennypincher3562

Hi Myser

I am familiar with the setup you describe. However, for some odd reason a plumber removed one of the valves when he was working on the boiler. Why, I've no idea.

Cheers
Pennypincher3562

Myser

The plumber may have replaced one of the lever valves with a fixed double-check valve to meet WRAS regulations.

Does one side look similar to this:



Can you post a photo of your filling loop arrangement?

pennypincher3562

Hi Myser

I examined my filling loop, and found a photo of one on the internet, that is pretty much the exact same, it has the same '15mm' markings on it.

The plumber removed the tap from the left hand valve that you see in the photo below (the one with the 15mm marking), leaving me with the single tap, that you see on the right hand side.

When I want to up the pressure on my boiler, I open or close the single tap that you see in the photo below.

A trivial detail that probably doesn't matter, the loop is fitted to my boiler with the tap to the left (in reverse of photo.)

Cheers
PennyPincher3562

Myser

It's as I thought - the left side is a double-check valve and the right is a normal lever valve.

It's most likely the lever valve that is letting by. Do you know where the main stop tap is in the property?

Turn the main stop tap off. You can then turn the lever valve off (lever horizontal) and disconnect the filling loop flexi pipe. Then slowly, turn the main stop tap back on. Check if it's a drip or a continuous leak from the valve.

You will get a little water spill out when you remove the filling loop.

pennypincher3562 wrote: »

A trivial detail that probably doesn't matter, the loop is fitted to my boiler with the tap to the left (in reverse of photo.)

Edit: Are you sure the lever valve is attached to the boiler and the double-check valve to the main water supply?

Can't you post a photo of your actual filling loop arrangement?

The direction arrows on the valves are key and indicate which way the water should feed into the system.

pennypincher3562

Hi All

Thanks for your advice. A plumber friend disconnected the loop, and plugged one end of it, as a temporary (and cheap) fix. The pressure is back to normal. The plumber showed me, the tiny amount of water that was leaking through the faulty valve - I was surprised that this small amount, could cause the pressure build-up.

I've cancelled my agreement with BG, and potentially saved hundreds of pounds (cancelled the boiler care contract, and inital callout.)

I've also learned some basics about the boiler, and would be able to sort the problem myself, if it happens again.

Cheers
PennyPincher3562

I_have_spoken

I've cancelled my agreement with British Gas, and potentially saved hundreds of pounds

Yep, a Power Flush would have been recommended due to the commission this would earn the BG technician, possibly also swap the pump & heat exchanger so the old parts could be Ebayed.