I have read numerous posts about the fitting an external expansion vessel but would like to ask something more specific regarding my particular boiler.
The Baxi in my garage (4 1/2 years old) is an instant and has caused quite a few issues with pressure when hot. The vessel has already been replaced by Baxi themselves but for a good few months it has started rising to 3 bar and if I crank the thermostat up full it can pop the safety valve.
I was recently told by an engineer that the vessel inside could not cope with the increase in pressure due to its capacity being reduced because of the stored water function, hence the over pressure when the heating is on high. He did also say the best way around this was to leave the internal vessel as it was and fit an external one.
The first question, would you agree with this diagnosis?
My second subject is about the fitting of an external vessel. I believe it has to go as near to the boiler return feed as possible, so is it a case of joining into the return pipe and connecting it to the external expansion vessel which I could fix at boiler height to the garage wall? If this is so I am happy to undertake this myself so long as their are no safety issues. I have previously relocated radiators myself and have no problem with pipes and joints or draining and refilling the system.
If all is well so far, we live in a slightly extended 3 bed detached, 11 rads but a couple of decent sized doubles downstairs. What capacity expansion vessel would you recommend, and any particular brand. I have seen them on toolstation for arould £20.00 rising to around £60.00 on others. Would a lower end suit my needs?
Thanks in advance and hope I am not asking too much.
best regards,
Mal
The Baxi in my garage (4 1/2 years old) is an instant and has caused quite a few issues with pressure when hot. The vessel has already been replaced by Baxi themselves but for a good few months it has started rising to 3 bar and if I crank the thermostat up full it can pop the safety valve.
I was recently told by an engineer that the vessel inside could not cope with the increase in pressure due to its capacity being reduced because of the stored water function, hence the over pressure when the heating is on high. He did also say the best way around this was to leave the internal vessel as it was and fit an external one.
The first question, would you agree with this diagnosis?
My second subject is about the fitting of an external vessel. I believe it has to go as near to the boiler return feed as possible, so is it a case of joining into the return pipe and connecting it to the external expansion vessel which I could fix at boiler height to the garage wall? If this is so I am happy to undertake this myself so long as their are no safety issues. I have previously relocated radiators myself and have no problem with pipes and joints or draining and refilling the system.
If all is well so far, we live in a slightly extended 3 bed detached, 11 rads but a couple of decent sized doubles downstairs. What capacity expansion vessel would you recommend, and any particular brand. I have seen them on toolstation for arould £20.00 rising to around £60.00 on others. Would a lower end suit my needs?
Thanks in advance and hope I am not asking too much.
best regards,
Mal
