help small tank in me loft is overflowing !!

[muzwhizz]

Hi Guys, have a problem with water overflowing from the smaller of my tank in the loft.. Took me a while to work out that this was coming from the loft after ripping up my floorboards. However this happened on Saturday night. I figured that the overflow pipe was frozen so the excess water couldn't escape. My solution was to tie the ballcock to the rafter with piece of string ( after draining half the tank with a hose pipe ) I've had a couple of baths and several showers since. I've still got hot water.
Is this correct ? is the water that i've been using what's left in the big heater tank in my airing cupboard ? Is this going to explode ? Break ?
I'm going to rush home and take another look with some proper lighting.
Your thoughts would be greatly appreciated..
I just have a normal shower. ( No power shower )

Thanks guys.

 

[Bahco]

Read this

 

[Hugh Jaleak]

Smaller tank of the 2 is likely the feed and expansion for the central heating. Doubt anything is going to break straight away, but if the ballcock's faulty, replace it, otherwise Bahco has given you a link to other possible issues.

 

[Burnerman]

The smaller tank is the central heating header tank - correctly called the flow and expansion tank. It should only have about 4" water in it, and this shouldn't vary. It has no connection with the other large tank, which is used to replenish your copper hot water cylinder as you draw water off for washing.
John

 

[muzwhizz]

4" You say... had closer to 14" and flowing.... that water was warm as well....is this correct ?

 

[Burnerman]

Lets get this right...you've tied up the ball cock so fresh water cant flow in, but the tank is still filling up to overflowing? Is water coming in via the expansion pipe, that curves over the top of the tank?
That would indicate a problem with your copper cylinder, in particular the heating coil within.
John

 

[muzwhizz]

No John,

Please let me explain...... The ballcock is tied to stop any water from flowing.... although previously the water was overflowing with about 14" of water in the tank not the 4" mentioned previously. Sorry for the confusion old bean....

 

[muzwhizz]

I'm off home now i'll let you know when i have another look. Hope my house hasn't turned into a swimming pool...

 

[Bahco]

Read this

Then drain some water out via a rad to leave you with 4 ins of water with the system cold,

Simples!

 

[Burnerman]

Good oh - thats saved you a bit!!
Time for a new washer for the ball cock, or maybe a new valve entirely (they don't get much use at all).
Once done, bale out the excess water in the tank until you're back down to about 4".
You can siphon it out, but don't get a gob full!
John

 

[Nige F]

The smaller tank is the central heating header tank - correctly called the flow and expansion tank. It should only have about 4" water in it, and this shouldn't vary. It has no connection with the other large tank, which is used to replenish your copper hot water cylinder as you draw water off for washing.
John

really correctly called a Feed and Expansion Cistern

 

[Burnerman]

Correct squire you win a cookie
John

 

[ColJack]

are there no adjustment screws on the lever arm? or can you not bend it down a bit?

 

[muzwhizz]

Cheers lads..... No swimming pool... untied the ballcock and the tank filled up about 7" I think i need new washer or valve. It must be sticking and kept on filling up. Didn't help with the cold blocking my overflow. I'll have a proper look tomorrow methinks.
Thanks again lads put my mind at rest.