Please Help! Overflowing Gravity Fed System

[acsmith1986]

Hi All,

I am not a plumber, but a fairly competant DIYer. I am having a problem with an old gravity fed hot watre system and am tearing my hair out trying to figure out what could be causing the problem.

So, what appears to be happening is the Larger tank in the loft fills until it lifts the Ball float enough to stop the flow. Then what seems to be happening is the Smaller tank is somehow being filled! it is not the small tank float valve (this is not leaking and is workig correctly) and if I stop the large tank by holding the float up with bungie cords the small tank does not fill. it is not overflow from the Large tank into the smaller as the water in the Large tank never reaches the overflow level. Obviously as the smaller tank fills it then reaches the overflow and water pours out the overflow pipe on the side of the house.

As the Larger tank seems to be forcing water into the smaller tank somehow the level drops in the larger tank, and the float valve allows more water in it then in turn forces more water up into the smaller tank and the cycle continues!

I thought the Larger and Smaller tanks were seperate (Larger for Hot Water system Smaller for Heating system) is this correct?

Can anyone explain why this may be happening and how I might be able to fix it!?

Thankyou in advance!

Adam.

 

[magicno1]

Basically my friend the coil in the hot water cylinder has a hole in it through corrosion so domestic water is entering the primary side and up into the header tank.
You need a new cylinder- simples

 

[Deleted member 7121]

As above split or hole in coil

 

[joni os]

As above. Check by tying up ball valves and wait for water level to be same in each tank. If looking for temporary fix,ie heating from boiler and hot water via immersion heater, it will be necessary to isolate BOTH the primary flow and return to cylinder coil.

 

[SimonG]

Another vote for split coil

 

[aplombier]

As above , coil died , time for new cylinder

 

[acsmith1986]

Hi guys, thanks for the replies, not exactly what I wanted to hear ofcourse! I may try the isolation fix and run the hot water using the emmersion as apposed to the boiler. Any rough estimates on getting a plumber to do the isolation fix?

 

[Dechko Enev]

Hi,
Where about is the property? If in London contact me on my email for a quote!
Regards,
DN BUILDERS

 

[acsmith1986]

Alton Hampshire

 

[jonnyswamp]

Hi,
Where about is the property? If in London contact me on my email for a quote!
Regards,
DN BUILDERS

A builder with 3 posts touting for work on a plumbing forum ffs

 

[Admin]

No rules against it I suppose. Can't see it working though.

All the more reason we need to sort out a 'find a plumber' thing for our members eh?!

 

[moonlight]

Looks like the your coil in your cylinder has gone, new cylinder unfortunately