Cold water tank in loft - vent pipe expelling water

[samday]

when i shut off the main it does stop. but after a while. i also have a shower pump is that makes a difference?

 

[Goldberg]

The vent pipe above my cold water tank in the loft is expelling water.

So is the cistern overflowing?

If not, why not?

Have you had any plumbing work done recently?

BTW, just in case you're tempted, do not, under any circumstances, cap off that vent pipe.

 

[samday]

the cistern is not overflowing from the overflow pipe, just from the vent pipe. I do not know why....

i have not capped it off, that would be dangerous.

have not had anything done recently.

 

[Goldberg]

OK, so water is entering the cistern from the vent pipe, but the water level isn't reaching the overflow.

Is this because:-

a) You haven't left it long enough for the water level to rise that far?
or
b) Someone is drawing off water somewhere?
or
c) You're winding us up?

 

[obiplumbkinobi]

Would need to see it it think, am running out of ideas here, secondary circuit? how big is your gaff? How long has this been going on?

 

[samday]

water is coming from the vent - and then i presume water is entering via the 2 outlets at the bottom of te tank, hence the watwer not getting to overflow level in the cold water tank.

 

[samday]

secondary circuit? my house is a normal 3 bed semi.

 

[obiplumbkinobi]

Goldberg, any ideas?

 

[obiplumbkinobi]

secondary circuit? my house is a normal 3 bed semi.

Is there a yellow pump in the airing cupboard, clutching at straws basically

 

[obiplumbkinobi]

Is the problem intermittent or continual?

 

[samday]

no yellow pump, just a red one which says grundfos. think this is for he heating circuit though....

problem is inermittent i think, although i only noticed it by chance today.

 

[holty]

for one. why is it now youve noticed this. because i take it you dont look at you cws evry day.thus being an instalation problem there is a formula for hot water vent pipes somthing like for every metre of head x40mm +150mm.that will determine the vent height from the water level.anyway its prob due to expansion of the water when hot.if its the case this happens when cold well i give up.

 

[obiplumbkinobi]

think it may be your kitchen mixer tap. but there are alot of variables, I would consult a reputable plumber or post alot of piccies.

last question, how high above the water level of the cwsc is the vent pipe?

 

[Goldberg]

Goldberg, any ideas?

Yes - he's wasting our time.

samday, you don't seem to be putting much effort into giving an accurate description of what's happening. For example, how long did you spend watching the water coming from the vent pipe? Was it dripping or gushing? How many times have you seen it happen? Over what period? Was it hot water or cold water? Have you been using the immersion heater?

 

[samday]

vent pipe rises auite a way above cold tank before bending over into it. i'd say about 1/2 metre....

i have noticed now it only happens when the shower pump is on if that matters?

when cold it does not happen.

sorry for all this guys.