Boiler pressure high since annual service

Mr_Ted

thor wrote: »

My boiler loses pressure going from 1.0 to 0 in a matter of months and because I'm too lazy to re-pressurise it, it oftens stays at zero for many months more. It has never once stopped working. I no longer worry about it running on zero pressure(although I have recently topped it up). I can't figure out why the low pressure appears to have no effect.

Running with zero pressure is dangerous as the boiler will not have enough water in it, and it can cause all sorts of issues, especially if safety features are NOT working, which they obviously cant be :eek:

Mr_Ted

roddydogs wrote: »

My MILs combi is 0.4 bar when warm, Im not getting involved as I dont want the hassle. Seems to work fine

This is also borderline low pressure and most boilers have a safety cut out at a designated low pressure point, usually about 0.5 or 0.6 bar, this is obviously not working:eek:

It doesn't take much effort to top up from the filling loop to 1 bar, just open the valves slowly until the pressure is reached, and then turn off

southcoastrgi

Mr_Ted wrote: »

most boilers have a safety cut out at a designated low pressure point, usually about 0.5 or 0.6 bar, this is obviously not working:eek:

unless it's a WB

thor

Mr_Ted wrote: »

Running with zero pressure is dangerous as the boiler will not have enough water in it, and it can cause all sorts of issues, especially if safety features are NOT working, which they obviously cant be :eek:

Will these 'issues' be obvious? If not can you tell me what to look out for.
I agree a boiler should not be able to work without water pressure but mine has been running merrily along for several months at 0 pressure.

diywhynot

You're assuming the pressure gauge is actually functional...they do fail.

Lgas

Mr_Ted wrote: »

:rotfl::rotfl:How can that be if the manufacturers literature, like most, says 1 bar :rotfl:

The higher the cold pressure the more expansion will take place which will raise the pressure, the more the pressure is raised the more likelihood of overpressure issues and the possibility of leaks and blown safety valves:p

Drop it to 1bar as is recommended

I don't really see why that is so hilarious. The OP's boiler will fail to operate below 0.7 bar. 1.5 is a perfectly normal pressure to set a boiler to, at that pressure, under normal operating conditions, I wouldn't expect the pressure to rise above 2 bar, unless there are problems with the expansion vessel. As the PRV opens at 3 bar pressure, it should not cause a problem but does give a little extra comfort room should the pressure drop slightly. 1.5 bar causing leaks, really??

Lgas

thor wrote: »

My boiler loses pressure going from 1.0 to 0 in a matter of months and because I'm too lazy to re-pressurise it, it oftens stays at zero for many months more. It has never once stopped working. I no longer worry about it running on zero pressure(although I have recently topped it up). I can't figure out why the low pressure appears to have no effect.

You clearly do not have the same boiler as the OP then, that boiler does have a low pressure cut out below 0.7, I know that for a fact. Also you are doing untold damage to your boiler running it with no pressure, pumps do not take kindly to being run dry.

Mr_Ted

Lgas wrote: »

I don't really see why that is so hilarious. The OP's boiler will fail to operate below 0.7 bar. 1.5 is a perfectly normal pressure to set a boiler to, at that pressure, under normal operating conditions, I wouldn't expect the pressure to rise above 2 bar, unless there are problems with the expansion vessel. As the PRV opens at 3 bar pressure, it should not cause a problem but does give a little extra comfort room should the pressure drop slightly. 1.5 bar causing leaks, really??

your right its not hilarious, its actually pretty sad that you don't understand that the manufacturers requirements are the standards that should be adhered to above all others, they are the one that are legally binding above any others

Also the comfort room as you call it, is also determined by what the manufacturers settings dictate

Leaks, yes REALLY, the higher the pressure the more sound an installation needs to be, so if there are ANY slight deficiencies, then the higher pressure will find these out and a leak WILL occur

Should not does not mean WILL NOT, as that depends on other factors that COULD be changeable

Lgas

I stand by what I have said, and see no point in debating this any further.

I believe my gas safe qualification is enough to prove that I do understand, thank you very much, and know what parts of the manufacturer's instructions are legally binding.

Lgas

I can't help myself - this is from the installation manual for the 30 CXI.

Fill the system until the pressure on the display reads at least
1.0bar.