combi boiler/refilling

dipsy

Hi I was wondering if anyone could help

I have a combi boiler about 3 years old

it seems to need topping up with water more than it used to, does anyone know why this would be?

thanks in advance

Ionkontrol

You have a leak somewhere.
Go round every radiator and check all the valves to see if any are weeping.

dipsy

surely there would be a big water mark/evidence?

I can't see anything obvious...... is there anything I can put into the boiler to seal wherever the leak is?

Hobsons_Choice

Ours was doing that, topped it up and now it leaks from the overflow pipe (outside).
It may just be a faulty guage?

gas4you

Could be the prv leaking. Could be the expansion vessel needs re-pressurising or even replacing.

When the heating is on, does the pressure rise very quickly to about 3 Bar?

dipsy

ok checked it, and does this make any sense, If I leave the filler pipe the one that runs from tank to cold water source connected then there is less of an issue?.... but in answer to gas4, its the red dial, the one they set as suggested min level...it is set at 4 bar..., not sure if it reaches 3bar really quickly... what would that indicate?
dont tell me knackered boiler as the guys I had come out left me withought heating/etc and the worcester/boch guy came out and said it was wired wrong.... and they came recomended....

macman

Whether you leave the filling loop connected or not does not make any difference, as the valve on the loop is fully turned off (or should be) once it has been repressurised. Is it continually leaking from the pressure relief valve?
It should not be reading 4 bar when cold!

gas4you

The dial needle should read about 1.2 Bar when cold. Your prv is designed to open at 3 Bar, so at 4 bar you will have a constant leak.

I would suggest you get this checked as well, because at 4 Bar it should be fully open and letting most of the pressure out.

Check that your filling loop is properly closed and not passing water through.

ariba10

gas4you wrote: »

Could be the prv leaking. Could be the expansion vessel needs re-pressurising or even replacing.

When the heating is on, does the pressure rise very quickly to about 3 Bar?

I go along with the above. The expansion vessel needs repressurising.

ariba10

Should have added that it is quite easy to do with the help of a car foot pump.

dipsy

ariba10 wrote: »

Should have added that it is quite easy to do with the help of a car foot pump.

Hi there, can you give me instructions :-)

ta