Dripping Central Heathing Header Tank Overflow Pipe

[John Widger]

A bit of an odd one this....

My wife and I don't like it hot so have set the thermostat in the hall to 16 so it is about 17 to 19 around the house. We were concerned that this wouldn't let enough heat get up to the cold water & central heating tank in the loft so I added so extra insulation (of the sliver foil bubble wrap type) around both of these tanks a couple of years ago. I also replaced the ball-cock in the header tank as this had failed. Since then we have been getting intermittent (one every few days or so) drips from the overflow pipe connected to the central heating header tank. As the water in this tank was nowhere near the overflow pipe I put it down to condensation.

We had to go away for a few days over the cold spell in December so upped the heating (19 degrees) and left it on for longer. When we came back the overflow for the central heating header tank was dripping every couple of minutes. I checked it out and again the water level was nowhere near the overflow pipe so was not overflowing. I took off the extra insulation around this tank and it appears to have helped but it is still dripping more than usual.

One other thing - when I fitted the new ball-cock it has a higher float level so I have about twice as much water in the header tank than with the old ball-cock, about 6 inches of water - this is still 4+ inches away from the overflow pipe.

Any ideas as this is starting to drive me mad - any help/ideas really appreciated.

 

[justlead1]

Hi. When the heating is on, the water you heat via the boiler expands. (25 gallons will become 26 gallons in volume when heated thro. 99 degrees) as a result the water level in the expansion cistern will rise. On cooling the level will drop. The problem may be as simple as bending the arm of the ball valve down, so as the expanded water on heat up will not reach overflow level. (Bend the arm between the valve and float, NOT as it enters valve. Good Luck

 

[sonray ltd]

We were concerned that this wouldn't let enough heat get up to the cold water & central heating tank in the loft

you don't want your heating going up into the loft. its a waste.

One other thing - when I fitted the new ball-cock it has a higher float level so I have about twice as much water in the header tank than with the old ball-cock, about 6 inches of water - this is still 4+ inches away from the overflow pipe.

Any ideas as this is starting to drive me mad - any help/ideas really appreciated.

water won't expand 4" in the f/e tank.

you need to check your water level when the system is running.
is the water hot/warm ?
is the overflow on its own or connected to the cws tank as well ?

 

[John Widger]

Thanks for your comments.....

Even when dripping the water is nowhere near the overflow pipe (4+ inches below) - the inside tank is dripping with condensation though.

The water is cold, not icy cold but cold enough. The overflow pipe only feeds the header tank, there is a separate overflow for the cold water tank.

Will try bending the ball-valve arm, did this when I fitted the new arm but obviously not enough. Tried to bend in in the tank but couldn't get enough force so will have to remove and then bend - one for another day as I have done my back in and don't want to go in the loft again and make it worse

 

[sonray ltd]

If after altering your water level, and you still have overflow problems [normally overnight] could be a hole in your cylinder coil.

does the cylinder coil know when its night time then ?

 

[NickH]

Even when dripping the water is nowhere near the overflow pipe (4+ inches below) -

If thats the case then whats the problem ?
The systems not overflowing and your first post said it was one drip every couple of minutes, I dont really see that theres a problem.

 

[sonray ltd]

of course it does..silly. No seriously, if there is a hole in the coil, the domestic water in the cylinder will gradually fill up your central heating system, pushing the level of water in the header tank up until it overflows. Not much domestic water is used at night and heating is off so it tends to build up over night.It also applies to the cold water storage tank overflowing, depending on which tank is the highest [ the lower one will overflow]

yes i do agree with you

 

[vdcplumbers]

Well, The best is get a local plumber ..they will fix your problem..you can pay them from £ 40.00 thats it why trying to figure out by yourself...> it might you will lost control in the loft then back ache again...I suggeting call a plumber,,,ok

cheers