ARISTON SX20 Loosing Pressure

[gesteves]

I have a Ariston combi boiler that has suddenly started losing pressure. Before I call out an engineer, can suggest what might be the problem.

The pressure is usually between 1 and 1.3, with the occasional topping up (every 6 months or so).

Yesterday the pressure fell to 0.5 and once I refilled it to 1.0, it fell to 0.5 again over a period of about 6 hours.

There is no discernable leak.

I would appreciate some advice on what the possible causes could be, so that I have some understanding of what the engineer is talking about.

Many thanks

 

[Rob]

There is usually an external PRV (red valve) under your boiler from which a pipe goes to out side.

Check to see if this is dripping. If not check all rad valves by the lifting the caps off.

 

[gesteves]

Thanks a lot - I will follow up.

 

[gesteves]

Hi again
I checked the red PRV and it seems to have lost it's 'spring' action. Normally I think you turn it to release pressure and then it springs back to the original position. The one on my boiler is loose. Can't tighten or loosen ti - just moves from right to left.
Does this mean it has to be replaced or can the spring mechanism easily be fixed?

Also, my boiler is boxed in with an access hole for the PRV. Will the box have to come off to fix this or could they do the work via the access hole?

Thanks again for your advise.

 

[Dan Robinson]

Depends on what one they have used. If is a standard red Calefi (ignore the spelling) then you change change the internals and just clean the fact of valve body.

Otherwise you'll probably need to change the whole valve - a picture would be nice.

my boiler is boxed in with an access hole for the PRV. Will the box have to come off to fix this or could they do the work via the access hole?

Dunno - send a picture.