Where is the water going?

[Malcolmkeith]

About 2 years ago I noticed water coming from the overflow of my central heating header tank.This tank is located in the loft but there is no access to it. The previous owner put all the water tanks in the tiny loft and then put the roof on!! (Honestly). I reasoned that if I shut off the stop cock to the tank the water level should only reduce very slowly and I could turn it on periodically to top it up.This seemed to work for the last 2 years. Every couple of months I would turn the stop cock on again and a little water would flow in to top the level up and then it would shut off after a few seconds. About 2 weeks ago I turned on the stop cock as usual and to my surprise loads of water (I would guess 3 gallons or so) rushed in to fill the tank. I did the same thing again a week later and again loads of water rushed in to fill the header tank.
I have looked at all the CH pipes and radiators and I cannot see any leaks anywhere. I'm sure if 3 or 4 galls of water leaked out it would have shown up by now. So I am puzzled. Where is the water going.

 

[Terry7556]

any chance of some photos?

 

[Hugh Jaleak]

I'd be making a way of getting access to the tank(s)! You dont know what is going on up there, it could even be the tank has frozen and split, in which case the water is seeping out and soaking into the insulation.....

 

[Malcolmkeith]

Thank you for your replies.

Terance:-
Here is a picture.(I hope). There is very little room between the chimney and the rafters. I am resigned to the fact that I will have to remove roof tiles and roofing sheet to get at it but even if I fix the overflow leak I am still wondering where the water is going.

Hugh:-
I don't think the header tank is leaking as it is directly above the wash basin in the bathroom and as there is only a layer of plaster board under the tank it would be showing a wet patch on the ceiling by now.

 

[Malcolmkeith]

Untitled

• Malcolmkeith
• 20 Feb 2012
• 1

Sorry - should have clicked on the photo.

 

[TicklyT]

Would creating a loft hatch in the bathroom be a possible way forward?

 

[Whitespirit66]

Can you check the any rad pipes under downstairs floor for leaks?

You definitely need to get the F&E loft tank sorted quickly, as you don't want to be running boiler or pump dry.

Another thing to remember, is that a faulty float valve in tank is not the only reason for overflowing. It can be caused by a fault in the hw cylinder's coil.

 

[Malcolmkeith]

Would creating a loft hatch in the bathroom be a possible way forward?

It could be and I have considered it. It would have to be from the other side of the tank and the problem is I can't see what there is behind the chimney so it would be a "cut and pray" exercise.

 

[Malcolmkeith]

Thanks Whitespirit66
>>Can you check the any rad pipes under downstairs floor for leaks?<<

Well this would be a mammoth task taking up all the floorboards in the house. Is there any way to avoid this?

>>You definitely need to get the F&E loft tank sorted quickly, as you don't want to be running boiler or pump dry.<<

Yes I appreciate that.

>>another thing to remember, is that a faulty float valve in tank is not the only reason for overflowing. It can be caused by a fault in the hw cylinder's coil.<<

But turning off the stopcock stops it overflowing.

 

[Hugh Jaleak]

You may not need to take all the floorboards up, the pipes may run lengthways under some boards.

Mirror and good torch may allow viewing of other areas, and depending what is under there may offer a clue. Soil will soak up a fair bit of water, but if there is a concrete oversite then i'd expect puddles of water to be noticeable.

 

[JohnD]

There is very little room between the chimney and the rafters.

Time to start a severe diet, perhaps, or befriend somebody small? A piece of ply laid across the timbers might make it possible to slide or crawl past the chimney.