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Unvented hot water cylinder but gravity fed system - help

HI. My aqualisa 340 mach pump is not working so I have been looking into replacing it.
What I found: The system is gravity fed (Tank in attic), the tank is a polar bear unvented. The old pump used to always pulse when turned on especially when hot ( I have solar panels) , I presume because the air has no place to vent to. I dont want to put in another pump if the whole system is incorrect. So what can I do, do I try to somehow vent an unvented system, or pressurized the system and get a different pump

4 Answers from MyBuilder Plumbers

Best Answer

Apologies, I have no knowledge on this system.


Answered 5th May 2020

You should get a qualified plumber in as there are a many safety devices and if you tamper and something happens your insurance will be null and void unvented can kill
Be safe


Answered 5th May 2020

you need to find a plumber who knows about solar hot water and is g3 registered to sort this out for you.


Answered 5th May 2020

Your best option is to fit an unvented cylinder this will enable to use solar as well. But you need to check the mains pressure first if it is sufficient to supply your cylinder. If the mains pressure is above 2 bar this would satisfy for an unvented cylinder. You need to call a qualified plumber with NVQ3 and G3 registered. If you fit an unvented cylinder it has to be notified to local authority building control.


Answered 16th May 2020

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