Cold water tank in the attic overflowing

[GGg]

Yep agreed. I’m just going to put a NRV on the outlet from the pump for the sake of £5 and my brain exploding. Will update after fitted.

 

[Riley]

Surely you can just isolate the pump on one of the flexible hoses

 

[GGg]

Surely you can just isolate the pump on one of the flexible hoses

Tried that. But either the isolating valves aren’t closing fully or I’m on the wrong track.

 

[GGg]

Ok so NRV fitted. Isn’t coming back into the tank at the moment but maybe because I turned off. Will check it over the course of the day to see if it’s come back. Thanks again for your help will keep you posted.

 

[GGg]

Ok so NRV fitted. Isn’t coming back into the tank at the moment but maybe because I turned everything off to fit the NRV. Will check it over the course of the day to see if it’s come back. Thanks again for your help will keep you posted.

View attachment 37114

 

[Riley]

I’d still look at fixing the issue as all you’ve done is mask it.

 

[Rob876]

Yes they can

So, true mixer taps with different supplied water pressures can create backflow when the taps are off? Within the body of the mixer tap?

 

[GGg]

So, true mixer taps with different supplied water pressures can create backflow when the taps are off? Within the body of the mixer tap?

My issue was the shower mixer rather than the taps. But was flowing through when off

 

[helon]

The small tank will fill your central heating the big tank fills your cylinder. Assuming it’s piped correctly the only place these to waters come close is in the coil in the cylinder, central heating water inside, domestic hot water outside. There could be a small pinhole in your coil meaning that when it heats and expands water from the smaller tank is able to pass into the domestic hot water. This then effectively makes it all one circuit no longer separate so the two tanks in the loft will try and achieve the same water level. This will only be the case though if the water level in the smaller tank is higher than that in the larger tank otherwise the same would happen only in reverse

Have traditional vented indirect system, in my case F&E tank base same level as large tank, so top level below, F&E tank overflows/steady trickle, maybe one bucket every 3 hours, also somewhat brownish water (water from taps crystal clear), guess it is coil, or could system be too hot (at one stage hot water was VERY hot), any suggestion?