Water Tank empty

[Dry tank]

Help !
Yesterday I turned off the mains to change tap washer in kitchen - ok
Today - no hot water ! In loft, the tank which feeds hot water cylinder is empty down to the outlet pipe.
The ballcock seems to move freely and no reason to suspect it is not working.
I have just tried a very quick turning off of mains, turning on taps etc trying to move air lock. Need to do it properly when I come back from work.
Any ideas other than the usual air lock cure of carefully opening taps from the bottom ? Why should the cold water be fine from all taps down and upstairs - but not reach the loft ??
Any advice would be appreciated

 

[JohnD]

how big is the tank you mention?

have you got a big tank and a small, or just one? If two, do either of them fill on the ball valve?

It may help to unscrew the ball valve in case it has stuck - they are so cheap, buy a new one on the way home so you can swap it - it will be quicker than repairing the old one.

You need a brass valve, where the water comes out of the top and has a sort of bridge to direct it downwards (this prevents dirty water being sucked back into the pipe in certain conditions).

If you want to, you can later dismantle the old valve, clean it, and repair it using a kit of parts. It is much easier to do this on the kitchen table when you have plenty of time and light. It can be quite handy to have a spare one in the loft ready for next time you have one fail (though they more often fail open, and drip)

 

[Dry tank]

Thanks for the reply JohnD

There are actually two big round tanks and one small rectangular overflow tank.
Both big tanks are empty. Both ball cocks move freely. And there is a single pipe which feeds both tanks. So, unless one ball valve had already stopped working ....... and now the second has stopped (which somehow seems unlikely) then I suspect the water is simply not reaching the ballcock valves ....

I will probably have a proper go at clearing an air lock, but might yet look at the ballcock valves.

Any other ideas anyone ??

 

[JohnD]

if they are both empty, I would suspect a stopcock is closed, either because one was turned off and has not been out back on, or was turned off and has broken in the "closed" position despite turning the handle.

As this is mains pressure water an air lock is not likely.

 

[Dry tank]

JohnD - a good point about the mains pressure, so unlikely to be an air lock.

However, I did not turn off anything but the stopcock under the sink - so, now I think maybe it could be both ballcock valves.


On the other hand .......... I think I might have closed another valve a few weeks back ......... maybe I did not open it fully ....... maybe it has been trickling ........... I will check later.

Thanks again. I will let you know the outcome.

 

[Agile]

Do you have cold water at the kitchen sink?

Both ball valves would not fail together. In any case they rarely fail closed!

Tony

 

[Dry tank]

OK - now I am home and have solved the mystery
a) it was nothing to do with my turning off the main to change a washer
b) I had not left any stopcocks half open

c) the two round tanks in the loft are connected
d) tank one - the ballcock valve was clogged - I have just cleaned out the cone
e) tank two - the isolating valve before the stopcock has never been open (this house is 5 years old)

So - the one tank is happily filling both. Thanks to all for the pointers.

One final question(s) then:
- should both tanks have their own stopcock filling ?
- why would I want the isolating valve closed on tank two ??

 

[JohnD]

If incoming water main feeds Tank 1

and

Tank 1 feeds Tank 2

and

Tank 2 feeds the taps

then it is correct to have fresh water running only into tank 1. This keeps fresh water flowing into tank 1, from tank 1 into tank 2, from tank 2 into the taps, so it is always fresh and always moving, and does not become stagnant. If the layout is different, please advise.

It has probably been done to increase the amount of stored water so you can have long showers, deep baths etc even with other taps in the house running, and for some reason the builders did not want to instal one large tank. Can you see a "size" on a label on the tanks?

I hope they both have close-fitting plastic lids, and insulating jackets? This also keeps mice, birds and spiders out of the tanks, and prevents growth of fungus or mould in there.

 

[petetheleak]

Bylaw 30 should apply to all .

 

[Dry tank]

JohnD

Incoming water feeds Tank 1
Tank 1 is currently feeding Tank 2
BUT only Tank 1 feeds the taps

Bearing in mind Tank 2 also has a ballcock valve, I suspect that someone simply forgot to open the isolating valve ....

Both are Polytank and read "Polylid 50" so I assume 50 gallons each.
Both have tight-fitting lids and are well insulated.

There are 3 showers and a bath in the house so in theory a lot of water could be used at any one time (but isn't)


Might it better to open both ballcock valves ?

Or to open Tank 2 and close tank 1 ??

 

[JohnD]

open Tank 2 and close tank 1

 

[Dry tank]

JohnD

I'll do that then - thanks for your help

Best Regards
Dry Tank

 

[Agile]

I would have said the it would be better to have both ball valves working.

As Tank 1 feeds the taps then tank 2 should be the one used if only one ball valve is in use.

Its possibly intentionally done to reduce the drain on the mains supply to prevent too great a reduction. It all depends on the water and hot water arrangements.

If the tanks dont ever run dry then just use the valve in tank 2.

Tony