After replacing the ball valve, thinking that was leaking and causing the overflow to go, I have just realised that warm water is coming up from the immersion in the bedroom up into the loft tank. Grateful for advice on what I should do to stop this, thanks
Could do with a little more information to answer this...
How is the hot cylinder heated - just the immersion, or is it also heated by the central heating?
If so, what type of central heating system; vented (i.e. with a little header tank in the loft) or sealed (no tank, but a pressure gauge and filling loop)?
How is the warm water getting into the cold tank? Via the feed pipe that goes from the cold tank to the base of the cylinder, or via the vent pipe that discharges over it?
If the cylinder is heated indirectly from your boiler then it is most likely that the primary water coil is perforated. Only option is to replace the cylinder.
the ball valve, thinking that was leaking and causing
OK, not an expert but....
the water can be heated by either the immersion of the Gas boiler. The central heating system is vented. Re the water getting into the tank, not sure about this. It is coming in from a large pipe that connects to the tank in the loft via the side of the tank at the bottom. Do I have to track this pipe to see where it connects to the immersion? Thanks for the feedback so far
No, if it is coming into the base of the cold tank, then that is almost certainly the feed out to the hot cylinder.
Options would seem to be, primary heating water escaping from the the heat exchanger coil in the cylinder. Check the relative heads of the cold tank and heating header tank. Is it possible for the water level in the header to be higher than in the cold tank? If it looks possible that this is happening then a new cylinder would be the cure.
Another option would be if you have any mixer taps that have a mains cold feed to one side, and the tap is "letting by" - forcing mains cold water back up the hot pipe. Can be particularly noticeable if you have a mixer like this that has a shower on it. (you should not use true mixer taps in these situations unless you have non return valves also fitted)
It'll be the primary coil.......I had the same problem......did my head in trying to find out the cause.....I replaced the washer. the valve etc. When I came to replace the cylinder I found a barsteward thread and had to abort the swap.ggrrhhhhh
replacing the ball valve, thinking that was leaking and causing
When you trace that pipe back I am sure you will find it goes down to the bottom of the cylinder (immersion as you call it). That is the cold feed to the cylinder.
Have a look inside the SMALL tank in the loft (the boiler header tank). Is this continually dripping but not overflowing?
Thanks for all the feeabck so far.
The latest in the saga is that the tank in the lost went into overflow mode last night even though neither the gas boiler or the immersion was on. So cold water is coming into the loft tank. I had assumed that it was only hot water that would come up due to convection. Is there any problem with draining the large tank right down so I can actually see the water coming in?
Heliotrope, I will look in the small loft tank and report back (why is life so complicated? Still don't realy understand why we need to have tanks of cold water sitting in the lost in the first plalce)
19:13, "Heliotr> > replacing the ball valve, thinking that was leaking and causing >
Been a busy afternoon. I drained down the lost tak and then could actually see the cold ater tricling up from the immersion into the tank. Based on John's advice, I went aroud and isolted the three mixer taps, this made no difference. So the prime suspect must be the shower which does have a mixer unit on. Not sure how to isolate this other than turning ff the mains. I took the shower off the wall and both the hot and cold pipes have what look to be small non-return valves built in. Took these out and put them back in, ensuring that they seemd to operate smoothly, replaced shower unit. If I wake up tomorrow, with no overflow dripping... BINGO!! If not, any ideas?
. I am afraid it looks more and more likely that the coil inside the cylinder is holed. It makes no difference if either the boiler or the immersion heater are on or not. It would seem that the small tank is higher than the large tank. The small tank contains the water that is inside the coil in the cylinder, so if the water can get out it must try to find the same level as that it started at.
The usual problem is a leak between the primary and secondary hot water circuits. A new cylinder is likely to be needed.
Bob
Make sure the heating and immersion are off. Get a rubber bung (or in extremis a carrot!) and reach into the small header tank and plug the outlet. Drain some water from the main tank, and see if it is still refilling. If not, and removing the bung from the header tank starts it filling again, then you have a leak in your cylinder's heat exchanger coil.
OK, I drained down the tank in the loft to confirm that water is coming up from the immersion. Sure enough, there was a steady trickle. I also checked the smaller boiler header tank. This looks rock solid, nowhere near over flowing. We recently had an extension put in with 3 new mixer taps and a shower. I isolated each mixer to see if this stopped the trickle, non did. Could not see how to isolate the shower but took the mixer part off the wall. There seemed to be a small non-return valve built into the inlet on both hot and cold. I tickered with them to ensure they could move in and out smoothly and then re-installed it. Fingers crossed that it was the shower unit "letting by". Monitoring the water level in the loft tank today thanks for all the advice, I will let you know
On Mon, 20 Aug 2007 01:31:52 -0700 someone who may be Patb wrote this:-
It would have been sensible to mention this somewhat earlier in the thread.
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