cold water tank overflowing

[gooner8973]

I am after some advice on a problem I have

Im havig a problem with the cold water storage tank in my loft overflowing so I had the float valve and a few days later it happened again so I got the plumber back, he checked it and found that when I put the hot water on not immersion heater as I never use that, the pipe from the cold water tank that goes to the hot water cylinder gets warm and the hot water is coming back up the pipe
Also the hot water cylinder in the loft 4 foot underneath the cold tank
Any ideas

 

[seco services]

sounds like a split cylinder coil.

is the little f/e tank for heating higher than the cws ?

 

[gooner8973]

no they sit on the same pedestal next to each other also I have had a new shower fitted with a electric pump would that cause any problems and I only overflows when I put the boiler on for hot water???















/

 

[seco services]

what tanks got the highest water level ?

is the shower fed both hot/cold gravity through the pump ?
but i doubt it being the shower bypassing as it only happens when hw on.

 

[gooner8973]

the cold water storage tank is higher been that way for years

 

[gooner8973]

and yes the pump is gravity fed cold off the cold tank and hot off the cylinder

 

[seco services]

whats the cyl stat set to ?

 

[gooner8973]

60 to 65

 

[seco services]

if you watch it happen can you hear/see the f/e ball valve filling ?
or isolate the f/e float valve and see if the tank emptys over a period of time. keeping your eye on the level.

 

[gooner8973]

im sure the level in the f&e tank has stayed the same as when i have watched the warm water go into the cold tank i havnt heard anything
but i will double check that tomorrow and if the level does drop what does that meen

 

[seco services]

coil split

if it was the shower or tap it would useally do it all the time.
all i can think is that putting the hw on the pump is forcing the water through a pin hole in the coil.

 

[gooner8973]

and if i do hear the f&e tank filling up does that meen the same that i need a new cylinder

 

[seco services]

if the coils gone yes.
but see what you come back with before thinking the worst

 

[gooner8973]

i have checked the f&e and it still seems to be ok and the water level is constant so what do you think it could be

 

[Jake1886]

Did you isolate the main cws feeding the F&E? If the level drops then I'd agree with seco and say you have a leaky coil.

Oh and up the Arsenal!