Boiler Problems

[Cane32]

Hi Everyone, I am new to this forum and I need advice from the experts. I have started having slight problems with low pressure on my POTTERTON ULTRA 2. I noticed the boiler was losing pressure so I topped it up and left it overnight (not in use), with no drop in pressure. As soon as I switched it on and ran it for a while, then shut it off and let it cool down, the pressure had dropped back to just over 2 above zero bar. I have checked for leaks on the pipework as far as I can, all rads, also no leaks. Can anyone give me advice as to the problem and a way forward, or have I missed something. Thanks

 

[Dan Robinson]

2 over zero

Where are you topping it up to?

Should be 1.5ish when cold. No more.

 

[Cane32]

Hi Dan, can you tell me why the boiler keeps losing pressure and dropping just above 0 untill i top it up from the filling loop back to 1.5 bar. Thanks

 

[Dan Robinson]

So it is dropping to 0.2? Not 2?


If the pressure is dropping then you have either:

A - a leak
B - a leaking pressure release valve caused by:

A- a guffed valve
B- a guffed expansion vessel
C - someone overpressurised the system at some stage and cause A & B.

 

[Cane32]

Correct with the pressure at 0.2 not 2.00. The original reason that I looked at the pressure was the boiler would not fire up and it kept clicking trying to start up. I then noticed that the pressure had dropped. I knew that I had to top it up and did so. This worked to fire it up, but since that time I have kept a close eye on it. I find that after the boiler cools the pressure has dropped again. I do not leave the system switched on if we are not in the house, for safety reasons. So I filll it up each time from the filling loop. With the diagnosis you have come back with, is it possible to isolate a) the valve or b) expansion vessel to find out where the root cause is. As far as I know it has never been over pressurised as we did have a BG contract, and has always been fine up until now. All we have had done in the life of the system is a new timer control and servicing. Is it possible to isolate the pipework from the boiler and pressurise that to check if the pipework is leaking?

 

[Dan Robinson]

The prv pipe should go outside by the boiler.

Does that pipe drip?

 

[Cane32]

Good afternoon Dan.
Yes the copper pipe outside from the boiler is dripping, the heating and hot water is on and if it stays on too long will all the water disappear out of the system through that pipe.
If that is the case are you any closer to solving the puzzle. When i switched the boiler on this morning it started CLICKING on trying to start up but it started o.k, is this all part of the same problem, and can i still run the boiler for the time being as long as i keep re-filling from the filling loop.

Thanks for your time and patience. Cane32

 

[Dan Robinson]

If that pipe is dripping, that is where the pressure is going.

Hopefully you just need a new PRV. Doubtless the boiler could do with a service, especially if BG have been looking after it.

Continually topping up the boiler will not do it any favours so I would get it looked at sooner rather than later.

As for the clicking - without know the make and model I can't say - and it would be tricky even if we knew.