Hi there,
Help needed to fix overflow problem I have a McDonald Engineers Hot Water System.
Spec: Indirect combination Clyinder.
Size 900x450mm. Storage Cap. 20ltrs colds & 85ltrs hot. Max. length of immersion hearer 350mm.
I have 2 main problems, 1 what is causing it to overflow and how do i fix it. 2. the tank is situation high up in a cupboard i can barely see into the top of the tank to reach the ballcock. Is there an easy way to possibly replace the valve from fitting outside the tank. Or could it be a simple problem e.g. washer. If so how do i change the valve? or replace the washer? I should mention the system is very old.
thanks.

Pauline, June 2008

thank you for your response. I have put my hand into the tank and can move the ballcock without any problem. It feels quite free to me. What I don't understand is how the water is going straight out of the overflow even though I'd emptied the tank and i'm only starting to fill it. I do have both inlet and outlet open.

I thought the water level would need to be much higher before the overflow came into effect. I'm not getting any water through any of the hot water pipes. There are 2 stopcocks, one (i assume is the inlet) at the top of the tank and the other at the bottom of the tank (i assumed that one feeds the water to through all the hot water pipes in the house).

I'f I switch off the bottom stopcock the overflow problem also stops???? Are there 2 overflow systems in this hot water tank. One for cold and one in the hot water storage tank. I originally thought it wat 1 large tank but when I look inside the top of the tank , with a mirror, it only holds a small amount of water compared to the overall size of the tank. Which must be the 20ltrs for cold water and the bottom section is 85ltrs (this must be filled up via cold water section. I've got other pipes which I assumed were put in when I got central heating put in. Is there any point in replacing the whole ballcock system that is in the cold water storage section of the cylinder or is it a problem in the hot water section. I cna't see how I can get access to that it looks sealed. As if there is a pipe which leads from the cold water section the the bottom of the hot water part of the tank. Any ideas?? Thanks.

Pauline, June 2008

1, maybe the ball valve is sticking causing it to overflow.

2, you need access into the top of the tank to gain access to the ball valve

hi-spec plumbing & heating, June 2008