Hot water being back flowing into Cold water tank

[Mark_James]

Yes but never have it on

 

[moonlight]

Sorry wasn't reading thread properly . If hot water is coming back up through the cold feed. It most likely is your cylinder, especially if the water level of your f&E tank is lower than your cold water storage tank.

 

[Mark_James]

Which it is, the heating is no problem. Only when the hot water is heated

 

[Tonycane]

so, f+e tank has more head pressure, so heating water is able so act against the hot water system head pressure, this will fill your cylinder via the faulty coil, this then travels back up the feed pipe and back in to your cold water storage tank. shine a torch thru the water at the bottom feed pipe, you will see the hot water if that makes sense

 

[Mark_James]

It does but I don't nor have evey had them on together. Always seperate

 

[Sedgy40]

Sorry wasn't reading thread properly . If hot water is coming back up through the cold feed. It most likely is your cylinder, especially if the water level of your f&E tank is lower than your cold water storage tank.

That's my thoughts too

 

[Mark_James]

Yes, I am sure that is what I am seeing at the fed pipe. Looks like clear stress of water coming into the cold water tank

 

[Mark_James]

Brill, that's gonna be expencive to fix!!!!!

 

[Mark_James]

Sorry to be a bit dim, but if the cylinder is split/hole in it wouldn't I see that in the water discolouration from the tips?

 

[Tonycane]

depends on the water quality in your heating system. confirm by turning off the cold inlet to the f+e, see if the water level drops.

 

[Best]

New indirect cylinder shouldn't be too expensive. Fairly straightforward job for a plumber, but will usually take several hours.
Just tie the ballvalve on the small heating tank (f&e tank) and see if the water drops in that. If it does lower, then has to be coil in cylinder perished.
You might want to consider if you could have stainless steel vented cylinder, or perhaps even if an unvented cylinder could be suitable for your needs, home and mains supply

 

[moonlight]

If you go down the invented root, there will be more costs. But no cold water tank in the roof, and if you decide at some point to change your boiler (I don't know what boiler you have) the cylinder would be t energy efficient .and suitabke for purpose. Just make sure the person who fits it is G3 certified and does all the appropriate checks. Good luck

 

[jtsplumbing]

From what I am reading you have a faulty hot water cylinder, replace it with a stainless steel one, (Nice long warranty) are you in a hard water area ?

 

[nickbrookes76]

i had a similar problem at an old house, and it turned out to be a mixer tap wasn't able to cope with the incoming hot water pressure and was leaking cold water into the hot supply. I know this doesn't exactly fit your symptoms, but just thought it may help.

 

[macplumb]

Can't be the coil due to overflow stopping. The overflowing would be constant due to a common return. so the coil would be subject to the same pressures when 3 port is open or closed.

Check the new float valve has not slipped (should be a part 2 float valve so can be ajusted. Put the ball to the lowest point) and bend the arm down a bit.
When water is heated it expands and hot water is less dense so will rise back to the tank by stratification giving you the effect you can see from the feed.