CH header tank overflowing when system is cold

jpscloud

Hi all, I wonder if someone knowledgeable might have some advice for me.

I have tried to be super-MSE this year by turning off my gas CH and hot water system completely, and just heating up water with the electric immersion heater when needed (just once or twice in a week).

When the system was entirely cold (the water in the hot water tank was cold as well) the overflow from the header tank (the little pipe under the house eaves) started to drip a little.

I ran the CH for half an hour, and the header tank stopped dripping. I then found that the pipe had started dripping again overnight, and it seemed to stop when I put the immersion heater on and ran some hot water.

A few days like this again, dripping overnight.

Yesterday and today the drip is a lot faster, I think it stopped yesterday afternoon/evening but doesn't seem to be stopping today.

I'm puzzled because I thought the overflow only happened when the system was hot - mine is doing it when the system is completely cold.

I think it has slowed down a bit now that I have put the CH on experimentally, also been running water after being out all day.

I'd be really grateful if someone could tell me what they think the problem is, many thanks in advance.

keystone

Your inlet valve to whichever storage tank is connected to the overflow is passing. Its cheaper for you in time and money to replace the while thing. Don't try and fix it. Fiver for the ballvalve and 15 minutes to fix. 10p for the washer and I'll bet you'll be cussing and swearing at it for a couple of hours.

If the overflow from the F&E tank is dripping when the system is hot then its most likely pumping over and thats a completely different problem.

Cheers

jpscloud

Hi keystone thanks for the reply! I honestly tried my very best to fix it last time, I even bought the fittings, but it is really inacessible for me and I don't have the strength to do what needs doing. I hate the idea of paying a plumber to do it, but it's my only option.

Edit: I have just realised I didn't explain "last time" - the washer in the header tank thing has had to be replaced twice (roughly every five or so years) while I've lived here. First time my dad did it, about 10 years ago, but he's now disabled and the second time I tried to do it but failed miserably - I just don't have the physical strength.

I wondered if it might be something different than the washer, as this time it is intermittent, when before it has always dripped constantly and got worse.

I'm relieved these symptoms don't indicate needing a new hot water cylinder or something though!

keystone

If the HW cylinder coil was ruptured you would have hot water coming out of the vent into your cold water storage tank. If its pumping over hot water will be coming out of the other vent into your feed and expansion tank.

Cheers

jpscloud

Sorry to be dim but where would the cold water storage tank be? I know which the header tank is - would it be next to that? Would I notice warm water coming out of the cold water tap if that was happening?

Another edit... it has definitely slowed and now I think stopped while the CH is on.

keystone

Its the big one! That is unless you've got some sort of strange hybrid installation.

Cheers

jpscloud

Aha thanks I think I'll go and have a look in the loft and see if I can find out where the water's coming from.

keystone

Good plan. CH off and listen for the drip drip drip which is almost inevitably coming from the ballvalve. If its not that then I'll very probably have to eat my hat.

<looks around for tomatoe sauce bottle just in case>

Cheers

southcoastrgi

you don't need any strenght to change a ballvalve just turn the mains off undo the connections & remove the whole thing from the tank & fit a new one, always replace the fibre washer on the tap connector (the bit you tighten back on) & the new ballvalve needs to be a part 2 ballvalve NOT a part 1

jpscloud

I can't tell where the water's coming from as it's stopped since the CH was on! I'll have a look first thing in the morning, when it always seems to be dripping.

At least your hat is safe for the night! :rotfl:

I really hope your hat is safe full stop - I'm nervous because my CH system is very old and the boiler hasn't been serviced for 15 years :eek:

I'm pretty sure the radiators need bleeding but I'm utterly incompetent... they're the type that have a sort of screw thing at the back rather than needing a key, if you know what I mean.

If it's just the ballcock/valve/washer thing that needs fixing, maybe I can get a handyperson in and ask them to do the radiators as well.

Fingers crossed for the morning!

jpscloud

southcoastrgi wrote: »

you don't need any strenght to change a ballvalve just turn the mains off undo the connections & remove the whole thing from the tank & fit a new one, always replace the fibre washer on the tap connector (the bit you tighten back on) & the new ballvalve needs to be a part 2 ballvalve NOT a part 1

I'm very embarrassed that I can't do it - the header tank is sort of tucked away behind a roof strut, and you have to be quite strong to undo the connections in a weird position - the plumber actually struggled as well. I honestly couldn't do it when I tried, and I would have loved to save the £65 (and that was five years ago :eek:)