Central Heating Pressure Problem

[kafkaian]

I have a Ferroli Optima Combi boiler and sealed CH system that's bee

running pretty well for at least 6 years. However, on start up afte this summer's shut down I have a pressure problem (hot or cold, on o off) which means having to top up twice a day. Now, I've cured a fe minor valve joint leaks, and there's no water being expelled out of th pressure relief valve and no water that I can trace anywhere else, bu I'm still having to top up. The situation's driving me nuts.

Any ideas please before I pull all my hair out? I can't see a proble with the expansion vessel - although I have taken a couple of rads of for decorating. Could this be the problem?

Agrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr

Thanks in anticipatio

-- kafkaian

[IMM]

Check the vessel charge pressure first. .

[John Rumm]

Assuming the system is cold and topped up to the right pressure, watch the pressure gauge as the boiler starts up and the system comes up to temperature. If it shoots up to a high pressure (i.e. more than 3 bar) then that might indicate the pressure vessle has either failed, or needs pumping up again.

[kafkaian]

Thanks for the replies so far. The system pressure never increase appreciably (hot or cold) just gradually decreases over a day.

I'll check the vessel though anywa

-- kafkaian

[John Rumm]

Worth doing, just to be sure. One way of testing this quickly is to find where the pressure release blow off pipe exits the house (typically its taken through a wall in 15mm pipe and then pointed down at the ground), and tie a plastic sandwidch bag or similar over the pipe so that it will catch any water coming out of the pipe (but not collect rainwater). Look at this at the end of a day. If it is empty then you know it is not a problem caused by excess pressure due to exapansion, or due to a leaking pressure release valve.

Assuming you eliminate those possibilities, you are back on the trail of a leak.

[kafkaian]

Cheers John. Appreciated

Ia

-- kafkaian

[kafkaian]

Still a problem and no sign of any prv leak. Ugh. Back to the drawin

board and a search for leaks that I can't fin

-- kafkaian

[John Rumm]

How much water are you adding a day?

More that a couple of litres ought to show up somewhere! If it was in an upstairs pipe then you would expect to see mark on a ceiling. If you have susspended floors downstairs and pipes run under them, then that is a place you could loose loads of water and not notice it.

[Phil Addison]

You have read the FAQ? Particularly Ed's on this very subject, linked off the group FAQ?

uk.d-i-y FAQ is at NOSPAM from address to email me