I have a Halstead Finest in an installation that has expanded to 17 radiators during our home extension activities.
I suspect I need an extra expansion vessel in this set up. The internal expansion vessel in the boiler is 7 ltr. I have no way of knowing the total system volume but my guess is that it must be around 120 ltr or so. (Say a rad is 6 ltr * 17 = 102 + pipework)
I've checked the pressure of the 'air' side of the existing vessel in the boiler and its around 1 bar with zero pressure on the water side.
The cold pressure of the system is 0.5 bar and it rises to 2.5 bar when hot. I suspect the PRV is opening slightly - if I take the system cold pressure to 1 bar it must lose water through the PRV because its down to 0.5bar when it gets cold again.
I think this system is only just coping with the water volume and needs an second expansion vessel.
Would that be right or an I missing something else.
Thanks
Ken
I suspect I need an extra expansion vessel in this set up. The internal expansion vessel in the boiler is 7 ltr. I have no way of knowing the total system volume but my guess is that it must be around 120 ltr or so. (Say a rad is 6 ltr * 17 = 102 + pipework)
I've checked the pressure of the 'air' side of the existing vessel in the boiler and its around 1 bar with zero pressure on the water side.
The cold pressure of the system is 0.5 bar and it rises to 2.5 bar when hot. I suspect the PRV is opening slightly - if I take the system cold pressure to 1 bar it must lose water through the PRV because its down to 0.5bar when it gets cold again.
I think this system is only just coping with the water volume and needs an second expansion vessel.
Would that be right or an I missing something else.
Thanks
Ken
