Hi all,
Thanks for having a great forum, I've found many a valuable tip over the years from here but I'm now up against a conundrum.
I've just replaced the expansion vessel of my inherited Saunier Duval Thema Condens F24 E combi but the pressure is still going very close (if not over) the 3 bar limit. Any thoughts what else could cause this?
The new expansion vessel was manufactured in 2016 and is a genuine part so while not impossible it's also faulty it seems unlikely. It came pressurised correctly (0.75 bar).
To me the only logical explanation is a blocked pipe between the central heating circuit and the expansion vessel.
I've had lots of woes with this boiler and can't wait to replace it but the new one will be going in with an extension later this year and I also plan to renew the entire central heating system so don't want to mix old with new and / or have to move a new boiler or have to work around the new one.
I've only noticed the high pressure issue since doing a load of work on it:
Good clean of pressure sensor - was caked up with magnetite and was stuck reading 0.4 bar
Replaced pressure release valve (leaking)
Replaced diverter motor (wasn't driving)
Replaced PCB (turns out it was not driving the diverter motor correctly)r
Good clean of the secondary heat exchanger (was caked up with magnetite)
After all that it was working like a champ but then noticed the pressure was going too high. A small spit of water came out of the valve of the expansion vessel too so all the symptoms seemed to fit with this being knackered but after changing it the over pressure still remains.
I plan to check the pipework to the expansion vessel is clear tomorrow but thought it worth asking if there's anything else people thought it could be?
Many thanks,
Dave
Thanks for having a great forum, I've found many a valuable tip over the years from here but I'm now up against a conundrum.
I've just replaced the expansion vessel of my inherited Saunier Duval Thema Condens F24 E combi but the pressure is still going very close (if not over) the 3 bar limit. Any thoughts what else could cause this?
The new expansion vessel was manufactured in 2016 and is a genuine part so while not impossible it's also faulty it seems unlikely. It came pressurised correctly (0.75 bar).
To me the only logical explanation is a blocked pipe between the central heating circuit and the expansion vessel.
I've had lots of woes with this boiler and can't wait to replace it but the new one will be going in with an extension later this year and I also plan to renew the entire central heating system so don't want to mix old with new and / or have to move a new boiler or have to work around the new one.
I've only noticed the high pressure issue since doing a load of work on it:
Good clean of pressure sensor - was caked up with magnetite and was stuck reading 0.4 bar
Replaced pressure release valve (leaking)
Replaced diverter motor (wasn't driving)
Replaced PCB (turns out it was not driving the diverter motor correctly)r
Good clean of the secondary heat exchanger (was caked up with magnetite)
After all that it was working like a champ but then noticed the pressure was going too high. A small spit of water came out of the valve of the expansion vessel too so all the symptoms seemed to fit with this being knackered but after changing it the over pressure still remains.
I plan to check the pipework to the expansion vessel is clear tomorrow but thought it worth asking if there's anything else people thought it could be?
Many thanks,
Dave