I was refering to the pressure in the expansion tank, this has to be done with no pressure on the system and somewhere for the pressure to go when you set it, you can't charge the pressure in the tank when your pushing against the system water if you follow, boilers used to have a chart saying what to set it it depending on size of system and head of water.Thankyou for your replies gaz1 and sg66.
At 1.6 bar on the digital read out the analogue pressure gauge within the cabinet is as shown in the pictures - ok its not calibrated but its position and the extent of the green zone suggests that the boiler could run in excess of 2.5 bar.
The boiler "locks out" on low pressure at about 0.8 bar - the needle on the analogue gauge being in the red zone then.
The ops manual dictates setting the pressure at between 1 bar - 1.5 bar and as there is a 0.5 bar increase when operating I am assuming this is when the boiler is cold - (it must be as if the boiler was running at 1 bar when hot, it would be 0.5 bar when cold and hence would not fire up as it would be locked out.
Its a ball ache.
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Get whoever fitted it back to sort it .Back in September I took the plunge and had a combi fitted in place of my reliable old Baxi back boiler and all seems well, except...
Since then, I've twice (it might actually be 3 times) had to re-pressurise the system. Is this normal? Or do I need to give my plumber a call?
The PRV is normally 3.5 bar.Thankyou for your replies gaz1 and sg66.
At 1.6 bar on the digital read out the analogue pressure gauge within the cabinet is as shown in the pictures - ok its not calibrated but its position and the extent of the green zone suggests that the boiler could run in excess of 2.5 bar.
The boiler "locks out" on low pressure at about 0.8 bar - the needle on the analogue gauge being in the red zone then.
The rads and tank are still same system with diverter valve sending water to heating or hot water leak could still be on either.Thankyou all for chipping in and guiding me on this - it is much appreciated.
At the end of the day my system is loosing pressure, 0.5 bar every 2 weeks, so I guess I have to identify from where. I am able to heat radiators or heat hot water or both at the same time from the boiler suggesting that there are 2 separate heating circuits.
With the weather now becoming warmer, we will not be running radiators and only heating hot water - so..... if the pressure in the system now remains constant would this suggest the leak is in the radiator circuit? And if it doesn't would this suggest leakage in the hot water circuit?
And if we didn't run the boiler at all, and still lost pressure, would this suggest I have a leaking prv valve? (Note there is no tundish on this).
Its annoying though - and I am surprised we ended up with a sealed system; it is an older house running off what was originally an open vented system with the header tank some 2 meters above the boiler creating what would have been some 0.2 bar or 2.9 psi pressure in the heating circuit - now changed to a sealed system running at 2 bar, (29 psi), and we wonder why we have some apparent leakage issues.
Exactly - but I am trying to isolate them one by one to hopefully identify which one is at fault.The rads and tank are still same system with diverter valve sending water to heating or hot water leak could still be on either.
this is the old system but the new system is hardly differentAt the end of the day my system is loosing pressure, 0.5 bar every 2 weeks, so I guess I have to identify from where.
With the weather now becoming warmer, we will not be running radiators and only heating hot water - so..... if the pressure in the system now remains constant would this suggest the leak is in the radiator circuit? And if it doesn't would this suggest leakage in the hot water circuit?
And if we didn't run the boiler at all, and still lost pressure, would this suggest I have a leaking prv valve? (Note there is no tundish on this).
Its annoying though - and I am surprised we ended up with a sealed system; it is an older house running off what was originally an open vented system with the header tank some 2 meters above the boiler creating what would have been some 0.2 bar or 2.9 psi pressure in the heating circuit - now changed to a sealed system running at 2 bar, (29 psi), and we wonder why we have some apparent leakage issues.
I see what you are saying - with heating to radiators closed and only heating hot water in the tank - I could still be loosing pressure on the return line circuit from the radiators.this is the old system but the new system is hardly different
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your only difference is the header tank and the feed pipe in white being removed
the 2 control valves ( red ) replaced with a 3 way valve with a motor at the junction point of the rads and the cylinder
when you shut down for the summer the valve closes to the rads whilst the cylinder valve remains open
the 3 way valve turns to close the rad side off but does become faulty and then you get both heating to the rads and cylinder at the same time
ive seen where the system dosnt leak at cold for all of the summer seasonmy system is loosing pressure, 0.5 bar every 2 weeks, so I guess I have to identify from where.
With the weather now becoming warmer, we will not be running anything
And if we didn't run the boiler at all, and still lost pressure, would this suggest I have a leaking prv valve?
Exactly that .I assume you were pretty sure the leak was under the concrete floor "somewhere" and the thermal camera allowed you to pin point the position exactly correct?
Now that comment I agree with 100%"...... the old system should have been pressure tested beyond the max operating pressure ......"