HELP NEEDED PLEASE!!

[midlandmackem]

In some serious need of help with my cold water tank in the loft. My overflow outside is nearly always streaming with water. I got in the loft and it was full up to the overflow (obviously!) After releasing hot water from downstairs it emptied down to the buoy limit which seems to be working fine as i waited in the loft until it filled up and shut off as the buoy should have done. At first i thought it had solved the problem until two weeks later and one hell of a soaked wall that it hadn't. Again it was at a high level but when i put my hand in to see if the buoy had filled up with water, the water was really hot? Unexpected for a 'cold' water tank. After releasing all of the water again i stayed in the loft for a good half an hour and it seems as though water is coming back up the same pipe as it goes down to the boiler! Hence maybe the water being really hot in a cold water tank.

Please could someone help if they have had similar problems.

Regards.

 

[gas4you]

Sounds like the coil in your HW cylinder may have a hole in it.

 

[gasmick2]

Hi it sounds like the usual problem with an indirect cyld they tend to get a pinhole in the coil inside the copper cyld then usally the heating header tank is higher than the water level in the domestic storage tank then when you have the heating on it pushes the domestic water back up the cold feed bit by bit its trying to get the level of the large tank to be the same as the higher small one just like if you had 2 bottles of water at the same level all is ok but make one higher and it will fill the other one up until a level is reached
Looks like its time for a new grade 3 cyld
hope this helps

mick

 

[JohnD]

Have a look in your loft

See if you have two water tanks - a large one which feeds the bath taps and the hot cylinder; and a smaller one which is supposed to top-up the central heating.

If so, look and see which of them has the higher water level (I don't mean depth within the tank, I mean the height of the water level inside above ground level)

Also have a look and see if either of them is filling up through the ball cock.

Tell us what you find.

Also please tell us if you have a shower mixer or basin mixer tap or if you have made any plumbing changes (including changing taps) in your house recently, and if the cold taps are supplied at mains pressure or at tank pressure same as the hot taps.

 

[midlandmackem]

We replaced the individual kitchen taps with a mixer tape. Will that make a difference.

Sorry guys, me and water really don't get on!!!!

 

[JohnD]

We replaced the individual kitchen taps with a mixer tape. Will that make a difference...

that could well be it, especially if it is an imported foreign tap.

If the high pressure (mains) cold water is able to leak through the internals of the mixer, it may be able to force its way up the hot pipe and eventually to force water back up into the loft tank.

To test this (after you've looked at the loft tanks as I asked earlier) get a torch and look under the sink. i hope you have fitted service valves that enable you to turn off the supply to the mixer tap. if so, turn them both off and see if the overflow stops within a couple of minutes.

 

[midlandmackem]

So if this does solve the problem will we need a new mixer tape? It was a cheap mixer tap from Aldi so it may well be an export!

 

[JohnD]

with luck that will be it

but carry out the test first

does your current mixer have a joystick?

 

[midlandmackem]

yes it does. Again will this cause a problem?

 

[JohnD]

IMO it makes internal leakage more likely, but I am just a householder. Some of the plumbers may know a good type of tap. You can also fit check valves but it seems to me they should not be required if the tap does not leak.