Hot water/Overflow

[grekko]

Thanks in advance to to everyone for their advice/help, here's the situation now:
I still have the overflowing water from the cold water supply tank, and I've had a new float valve fitted, but the tank is continuing to fill and overflow(but not from the valve inlet).......the water in the tank is almost tepid at times. What has become noticeable is that the overflow will still run , even if it's only a trickle, hours after both the C/H and Hot Water is switched off at the boiler(cylinder thermostat checked and not faulty)......plus the hot water takes forever to get warm at the bathroom tap, much longer than previously.....there's also the problem of a reducing supply of hot water, it eventually runs to a trickle and I have to attach the washing machine hose to the hot tap to get a decent flow again (but that doesn't last for long after running the hot water).......had plumber/C/H engineer in and they are puzzled so you can imagine how worried I am becoming at this unsolveable? problem.......C'mon guys please please HELP!!!!!

p.s The central heating appears to be working fine with no problem getting radiators warmed up.

 

[picasso]

You could have cross over from a mixer tap, washing machine not connected properly or anywhere hot and mains cold water are mixed, usually its a non return valve that has stuck so try and isolate one thing at a time until you find the culprit.

happy hunting.

ps start with shower if you have one.

 

[grekko]

You could have cross over from a mixer tap, washing machine not connected properly or anywhere hot and mains cold water are mixed, usually its a non return valve that has stuck so try and isolate one thing at a time until you find the culprit.

happy hunting.

ps start with shower if you have one.

Where might I find the non return valves that I could check?

Water setup in house is as follows:
Boiler in Kitchen supplies both hot water and C/H
Hot water Cylinder in airing cupboard on first floor,
C/W and F&E tank both on level surface in loft above first floor.
Taps in kitchen and Bathroom monobloc (fitted 5 plus years ago)
shower is electric heater type.
does any of that help?

 

[picasso]

You have to isolate each tap or mixer or w/machine one at a time and see if the trickle stops, might be worth turning off the mains water and if the trickle continues it could be the coil in the hot water cylinder.

 

[HERTS P&D]

Is the bottom of the cold water tank level with the bottom of the expansion tank?

Or is your expansion tank higher than the cold water tank?

Andy