Cold water tank in loft - vent pipe expelling water

[obiplumbkinobi]

What?!! No it's not!

Well that's gone and spoilt my bit of fun.

BTW, how many suitcases do you have that hold 25 gallons?

Well duty isn't that free anymore, it's not water I'm talking about

 

[samday]

Hi again, thanks all for replying

The vent pipe is over the large tank, the cold water tank that supplies the hot water cylinder and bathroom cold taps. The vent pipe, that u bends over the tank is spilling water.

 

[Goldberg]

Do you have a non-return valve on the cold feed to the cylinder?

What happens if you turn all mixer valves to the fully cold position (with no water flowing)?

 

[obiplumbkinobi]

Thanks for reply, is it happening continually? is there a small tank in the loft and if so, is it above the large tank?

 

[Goldberg]

You still haven't read all the information obiplumbkinobi.

 

[obiplumbkinobi]

Do you have a non-return valve on the cold feed to the cylinder?

What happens if you turn all mixer valves to the fully cold position (with no water flowing)?

Little confused there Goldberg, Non return valve on the cold supply to the cylinder? not come across that, can you explain?

 

[obiplumbkinobi]

Sorry GB, will re read

 

[samday]

the small tank is on the same level as the big one, but is shorter, so the water level would be lower. quite a lot lower.

there is no valve on the cold feed, except a gate valve and that is fully open as we have hot water from all taps and at a normal flow as usual.

i turned the mixer to fully cold positin, the lever on the shower and still the same...

 

[JohnD]

I don't have an immersion heater so have ruled out that failing...

But you do have a Hot Water Cylinder heated by the boiler, do you?

 

[Goldberg]

Little confused there Goldberg, Non return valve on the cold supply to the cylinder? not come across that, can you explain?

If a mixer valve was leaching mains cold through to tank hot, then the CSC water level would rise, unless there was a NRV on the cold feed, in which case it would come out of the vent instead.

 

[obiplumbkinobi]

Thank samday, I was trying to ascertain if you had a leak in the cylinder coil. eg. heating system filling up the cwsc. Goldberg was seeing if a mixer valve was bypassing and pushing mains water up the hot feed.

Has this problem recently occured

 

[samday]

yes the hot water is heated by a boiler. it is an olde boiler. a potterton flamino. it seems fine though. i had h/w on today thismorning and this evening.

 

[obiplumbkinobi]

What temp is your hot water? is there a pipe bent over the small tank?

 

[samday]

water temp from taps seem normal. the small tank as a vent pipe too and that is fine.

 

[obiplumbkinobi]

Is the vent running all the time, until you shut off the cold main?