Cylinder Venting constantly

[jacarutu]

I have a mains pressure system with a large cylinder in the airing cupboard. It is fitted with a vent valve on the side which is constantly letting hot waterout of the cylinder into an open cup. In the winter the pipe which runs down the side of the house froze and water back filled the pipe and flowed out of the open cup and through the lounge ceiling.

I put a T into the pipe and fed this into a 25 litre water bottle. If the pipe outside froze while i was at work, the water went into the bottle and not the ceiling.

The summer is here and the bottle is filling up every 2 days so i have closed off the tap on the T piece directing the flow back outside.

My query is, why is the cylinder venting about 13 litres of hot water a day as i cant afford to be throwing this energy away?

Do i have a fault in my system somewhere which causes it to overpressure or is the vent valve faulty.

Plenty of hot water available and heating upstairs is fine. Rads downstairs never get properly hot despite bleeding and flushing.

 

[Boilerman2]

What pressure is being indicated on the pressure gauge?
What make & Model is the UV Cylinder
you must get this problem sorted it will be costing you a fortune on your metered water supply bill!

 

[commercialman]

13 litres of hot water a day as i cant afford to be throwing this energy away?

Do i have a fault in my system somewhere which causes it to overpressure or is the vent valve faulty.
.

Could be a number of issues , T&P relief valve faulty , air gap non existant , Ex vessel depleted/diaphram split , PRV faulty , stat faulty , MV stuck open etc etc..........these units are seldom serviced on an annual basis.

 

[adlplumbing]

recommend you get some one in with unvented quals to have look

 

[xr4x4]

Is it a megaflow?

If so, have you followed the intructions on the side to recharge the air gap?

 

[Corgigrouch]

OP.. If you have water going where it shouldn't then this is a pretty good clue that there is a problem.... How many months did it take you to figure out that you shouldn't have water dripping through your ceiling????


Your first action is to reinstate the air bubble, if it is a megaflow that is... The instructions are on the side of the cylinder..... If it isn't a Megaflow then you will need to call someone who is qualified to work on unvented cylinders...

 

[jacarutu]

Yes it is a Megaflow. There is a label on it which you can read once you empty the airing cupboard and climb round the side of the cylinder.

Followed the instructions and it gurgled for about 40 mins. All seems well Thank you all.

Will pop round the neighbours now as they all had water through the ceiling last winter and have had to have repairs done.

In my case it was 6 hours of water running from the ceiling while i was at work. Thawed out the pipe and lagged it outside. 2 days later same again, water throught the ceiling. Started thawing out the pipe every morning and night and covered the lagging with roof insulation taped in place. Froze again during the night. It was -20C apparently, but for all of us who have the same system (6 houses) with 6 ft of copper pipe running down the outside of the house, it was frustrating and expensive getting the repairs done.
Haven't found any lagging that fixed the problem as it freezes at the bottom of the pipe and eventually seals the end.

I think in the end we all had about 3 weeks of water running into buckets, bowls and basins.

Thank you all again and fingers crossed.

 

[Corgigrouch]

If you had had the fault fixed when you first noticed water leaking from the pipe then you could have saved yourselves a lot of bother... leaking from this pipe denotes that a safety device has operated.

 

[jacarutu]

Yes you are right. The average guy like me has no understanding of pressurised systems. The pipe drips on all 6 houses constantly.

We now have some idea why.

Thanks again