Combi when cold = 1.7 bar, when hot= 2.6 bar

[sooey]

Surely he would fire up the boiler and he would notice it then? He didnt even turn the heating on!!

Then he's a numpty.

 

[MANDATE]

If the prv has never been opened and it's not leaking from there then there must be a leak elsewhere.
If it's leaking when hot I would say 'expansion vessel' and 'prv', but leaking when cold by 0.2bar is not expansion vessel in my opinion. Most likely related to the new radiator and valves.
Is there a way of isolating the boiler from system to prove which side the leak is on

 

[robbieee]

Half a bar. 1.0 bar cold 2.0 hot is perfectly normal. Most vessels are charged to 0.8 of a bar as well.

Not sure what that is in answer to?

 

[robbieee]

If the prv has never been opened and it's not leaking from there then there must be a leak elsewhere.
If it's leaking when hot I would say 'expansion vessel' and 'prv', but leaking when cold by 0.2bar is not expansion vessel in my opinion. Most likely related to the new radiator and valves.
Is there a way of isolating the boiler from system to prove which side the leak is on

I dont know if its leaking when its hot as i dont want the pressure to rise even further. Not sure about isolating the boiler.

I have checked all the pipe work and it all seems fairly water tight. Put Tissue paper around the joints overnight and nothing looks like its leaking.

 

[Dan Robinson]

Half a bar. 1.0 bar cold 2.0 hot is perfectly normal.

Only on sh|t installs.



IMHO of course .

 

[MANDATE]

Its in answer to Dan who thinks anything over 0.5bar increase is excessive.

 

[sooey]

You've said that the pressure drops by 0.1 bar over a couple of days and rises to 2.6 when hot. That's a very small drop (may have been there before). What is the pressure when cold? Did he run any new pipework below downstairs floor level?

 

[robbieee]

You've said that the pressure drops by 0.1 bar over a couple of days and rises to 2.6 when hot. That's a very small drop (may have been there before). What is the pressure when cold? Did he run any new pipework below downstairs floor level?

Its 1.7bar when cold at the moment. He only ran new pipe work upstairs. He took the feed and return from another radiator on the other side of the wall.

 

[Dan Robinson]

Its in answer to Dan who thinks anything over 0.5bar increase is excessive.

To me it is. And signifies an undersized vessel or one that's charge has gone.

My system has a 0.15 bar pressure rise from cold to hot.

Mind you - you should see the size of my expansion vessel .

 

[MANDATE]

The system was drained and re filled and any air in the system may still be finding it way out via the automatic air valve. This would result in a small pressure drop for a limited period so how many days have you had the problem

 

[robbieee]

The system was drained and re filled and any air in the system may still be finding it way out via the automatic air valve. This would result in a small pressure drop for a limited period so how many days have you had the problem

Just noticed a couple of days ago, new rad was fitted 5 days ago. How long should the small pressure drop last for if it is the auto air valve?

 

[CBF]

Mind you - you should see the size of my expansion vessel .

I hate men who boast

 

[Dan Robinson]

Seriously its huuuuuuge

3' tall at least .

 

[robbieee]

I still don't get how it can be the expansion vessel if there is a pressure drop when cold?

Does that mean i have a hole in the expansion vessel diaphram? Why would the expansion vessel need recharged? Is the air escaping? confused.com lol

 

[sooey]

Dan was referring to the expansion vessel in relation to the excessive pressure rise when hot.
The small drop over a couple of days when cold could be a very tiny leak anywhere on the system.