Ideal ISAR HE boiler losing pressure???

[ramo]

Hi all

My ideal boiler is losing pressure over a day or 2. We have had a few plumbers out which has resulted in them changing the air vent and the pump. Still problem continues cant see any leaks on radiators. The pressure falls to 0 when the boiler is not being used but increase when the Heating is on????

Can anyone help

 

[scatmanjohn]

So, if you put it to 1 bar and then leave it overnight, turned off ,it drops?

Yes/No?

If you put it to 1 bar and then turn the heating on, how high does the pressure go?

Have you checked the pressure relief pipe to see if it is dripping?

 

[ramo]

Ye if I turn it off it drops to 0.And if I put it to 1 and turn heating on its goes to 2.5/3 ???


Is that the pipe outside???

 

[gas4you]

You need to have the expansion vessel pressure checked, see FAQ's, but as this requires the removal of the combustion chamber front and the fan on this boiler, it is a job for a competent RGI, not any of those you have had round so far from the sounds of it

 

[shambolic]

Sounds like Exp vessel or system volume too big for existing vessel in boiler. When it heats up and goes above 3 bar the safety valve opens and releases excess press to outside. Then when boiler cools as you have also lost water it will go lower than starting pressure.

 

[scatmanjohn]

Then when its sorted get the person who fit the pump and aav to give you back any money that you have paid him.