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Andrew Smith
Andrew Smith, Plumber
Category: Plumbing
Satisfied Customers: 3767
Experience:  City and Guilds qualified plumber
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Hi. I have an apparent problem with the unvented pressurised

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Hi. I have an apparent problem with the unvented pressurised cylinder supplying hot water to taps and showers. We had a new sink and unit fitted two days ago on the ground floor of our three storey house. The plumber, recommended and seemingly competent, turned off the water in order to do the work but since then hot water pressure tails off within seconds to nil in all outlets on all three floors. We have normal mains cold pressure. The house has had a water softener since new as we in a very hard water area. Pumps and electrics supplying the cylinder seem fine and central heating working too. I have checked the line strainer which is pristine; the mains cold supply to the cylinder is regulated by a combination pressure control valve at 1.8 bar. The pressure dial adjacent to the pressure relieving valve is showing just above zero. I have tried draining down the tank via the lowest tap in the house then depressurising from the pressure relieving valve and hot water flows into the tun dish OK but although the pump can be heard operating and pipes attached to it are hot, there is no heat in the pipes leading out to the taps and although at first the pressure tailed off rapidly, there is now no flow at all. The cylinder is a Gledhill Accolade 210L. E have a maintenance agreement with British Gas who came out this morning but won't touch it because they reckon it's due to 'third party interference' by the plumber! This seems a bit unlikely, all he did was turn the water off and back on.
Any suggestions would be very welcome.
David Bartlett, Basingstoke, Hants.
I hope your plumber has got his unvented ticket, otherwise he should have been nowhere near it.
If you have no water coming from the taps it could be an air lock.
When you run the lowest tap as fast as you can do you get gurgling and spitting at the tap or does it just die?
Customer: replied 4 years ago.
Initially a bit of both, the hot taps have for a while been spitting air when first opened but the would flow normally. Since the plumber did his stuff we had , at first, spitting then flow then dying, now we have absolutely nothing coming out of the taps, neither air nor water.
Ok, run through this on page 13 and let me know how you get on.
Customer: replied 4 years ago.
I couldn't click the link but am assuming you meant section 7.6-7.8. I have drained the cylinder, the strainer is clean. Should I refill the tank with hit taps closed or open?
Try this - page 13;

But you appear to have the same manual, yes 7.6.

When you refill turn the taps off but leave the highest tap open, refill until you get water out of the highest point and then turn off.

You should have water through all the taps now.
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Customer: replied 4 years ago.
No luck. Plumber has been back today. Main problem is non-functioning combination pressure control inlet valve. Also valve leaking on expansion chamber. British Gas coming back today, should be covered under our maintenance policy. Shame their man didn't really do a proper diagnostic on Saturday , could have been sorted by now.
Thanks for your advice though. Will recommend JustAnswers and give positive feedback to you.
David Bartlett