High pressure building in hot water tank

DriveSkill

Hi,
We have a Solar Hot Water system which is running pretty well at the moment with the weather but we appear to have a problem with the pressure increasing beyond 6-bar causing a release valve to open and dumping water onto the floor of the hotpress!
So I know as the water temp increases the pressure will go up but how is that supposed to be handled - do we have a fundamental fault in how our system is installed ? Should that pressure be released somewhere else ? I know dumping the water onto the floor is not an ideal scenario - we did have a plumber before tell us that should have been piped out but is that release valve the intended mechanism to release the pressure or is it more of a safety feature and not really intended to "fire".

Thanks

Outkast_IRE

you need a solar installer to come out and investigate why the valve is activating. The expansion vessel may be gone on the system or the system is overheating and pressure rises as a result.

Your plumber was right though that valve should be safely piped to a tundish and then on to a drain or at a minimum a collection bottle or drum. It could potentially be scalding hot water and steam , very dangerous not to pipe it correctly in a closed system.

DriveSkill

Trying to get a plumber is near impossible but I am trying :-)

Ideally I would like a plumber to come and do a complete assessment of the system and remediate any issues and bring everything up to best practice but I've tried contacting several and people promise to call out but never show or one guy did, even gave an estimate but then stopped responding to messages and never saw or heard from him again :-(. I dont know if people just dont want to "fix" someone elses problems or what it is. The system was installed when we converted the attic back in 2012 and in hindsight it might have been better to get a solar specialist rather than asking the plumber as part of the attic work to do even though at the time he said it was "no problem"

Clodi

[QUOTE

Your plumber was right though that valve should be safely piped to a tundish and then on to a drain or at a minimum a collection bottle or drum. It could potentially be scalding hot water and steam , very dangerous not to pipe it correctly in a closed system.[/QUOTE]

Sorry to jump into your question but please may I ask why a tundish is needed? our pressure relief valve has a pipe attached that runs outside into a gutter.

Wearb

Clodi wrote: »

[QUOTE

Your plumber was right though that valve should be safely piped to a tundish and then on to a drain or at a minimum a collection bottle or drum. It could potentially be scalding hot water and steam , very dangerous not to pipe it correctly in a closed system.

Sorry to jump into your question but please may I ask why a tundish is needed? our pressure relief valve has a pipe attached that runs outside into a gutter.

---

So that you can see if it's leaking.

stoneill

I though the water should go to the expansion tank first and when that overfills then out the overflow pipe?

Outkast_IRE

stoneill wrote: »

I though the water should go to the expansion tank first and when that overfills then out the overflow pipe?

A solar system is a closed system no expansion tank.
its not like an open heating system with an expansion tank.

Calahonda52

Clodi wrote: »

[QUOTE

Your plumber was right though that valve should be safely piped to a tundish and then on to a drain or at a minimum a collection bottle or drum. It could potentially be scalding hot water and steam , very dangerous not to pipe it correctly in a closed system.

Sorry to jump into your question but please may I ask why a tundish is needed? our pressure relief valve has a pipe attached that runs outside into a gutter.[/QUOTE]
https://www.viessmann.co.uk/heating-advice/what-is-a-tundish