Bubbling/Boiling Water in Loft Tank/

The heating is making a racket. It's hard to describe but there's a metallic clanking noise followed by a general racket. This usually happens soon after the system comes on in the morning and then again in the evening.

The arrangement we have is a water heater with a cold water tank directly above it, and directly above those, but in the loft, another water tank. I'm a novice at this but as far as I can tell the problem is in the tank in the loft. What happens is that water feeds into the loft tank and the loft tank starts bubbling. The bubbling causes the general racket. There's steam coming off the water in the loft tank so it seems to me that boiling water is being fed into that tank. Now I'm not totally convinced this should be happening. The water up there is a disgusting shade of brown too.

Does anyone here recognise this description? Can anyone tell me what's going on? Is it easy to fix?

The arrangement sounds like that under the heading 'What are those tanks in the Loft For?' which I found here

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from only one of the tanks is in the loft.

Many Thanks in Advance

Reply to
Sensibleness
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============== The tank in your loft ( the bubbling one) is a 'header' tank for the central heating.

I think your pump is probably on its last legs. Additionally your system may be in need of flushing. Both these jobs are DIY jobs if you're reasonably competent.

Do your radiators and hot water tank get hot and if so do they do so as quickly as they used to before the problem started?

Cic.

Reply to
Cicero

The problem is showing itself at the Central Heating header tank. There could be any number of causes. A duff pump being in the frame, for sure.

Do use the boiler until this problem is resolved, use the immersion.

Reply to
Ed Sirett

Your thermostat has stuck on. Turn off and unplug / isolate the immersion heater (likely culprit), likewise the C/H boiler.

Be careful washing your hands afterwards - your hot water supply is probably scalding !

It shouldn't be too hard to fix, especially if it's the immersion. Swapping thermostats is a simple enough DIY job, with the relevant "Reader's Digest big book of fixing stuff" to hand.

A boiler gone berserk could be a harder problem to fix. Depends on where its thermostat is, and if it's beyond the "no user serviceable parts inside" barrier.

Reply to
Andy Dingley

Isn't this the immersion overboiling and the expanding hot water feeding back into the CWT?

Sounds like you need a new thermostat on your cylinder.

dg

Reply to
dg

============= Since the problem seems to coincide with the switching on of the CH boiler it's more likely to be associated directly with the CH rather than the immersion heater. But it's a simple matter to test for this simply by switching off the immersion heater and then check if the problem still occurs. If it does so then you can probably rule out the immersion heater.

Cic.

Reply to
Cicero

It is. I forgot to mention this.

We've actually got a variety of Home Care Three Star Service Help Agreement Thingies and as far as I can tell from the colourful diagram we are covered for this part of the system, unless it means a new boiler. We did call them out previously but of course the system behaved perfectly till they left. They are coming again tomorrow and this time I'll be able to give them a better idea of what the problem is.

I asked this question here partly to see if the situation was dangerous and partly to see whether there was a button I could press or a switch I could flick to take care of it.

Many thanks for all the replies.

Reply to
Sensibleness

The last couple of days we haven't had the heating on and we have still had the problem. That said as far as I can tell it also happens when the heating comes o

Reply to
Sensibleness

The last couple of days we haven't had the heating on and we have still had the problem. That said as far as I can tell it also happens when the heating comes on but presumably this is because when the heating comes on the hot water comes on too. I haven't yet got round to isolating each part of the system to see when the problem occurs.

cheers

Reply to
Sensibleness

============== You said that the water in the 'bubbling' tank was discoloured and steaming.

I assume that this tank (in the loft) is much smaller than the other two tanks and that would confirm that it is the CH header tank. If the problem is an over-active immesrion heater then you would expect the water in the larger cold tank in the bathroom to be bubbling and discoloured and your tap water would also be discoloured. For safety reasons you should switch off both CH and immersion heater and and run off hot water until it runs cold (noting any discolouration). Then try CH or immersion heater alone to see what happens. I think it is most likely a CH problem as stated in a previous post because the hot and cold water system is isolated from the CH heating water unless you've got a very peculiar system.

Cic.

Reply to
Cicero

The OP said "...system comes on in the morning...". That's not going to be the immersion heater. whcih would take a few hours to get to boiling point.

Reply to
Ed Sirett

The man from the Three Star Service Agreement Thingy says it's the Boiler Thermostat and it'll be fixed on Wednesday. Which makes a change because he usually says, 'Not covered mate. It's going to cost you £300. And that's if we can find the parts.'

Thanks

Reply to
Sensibleness

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