Why might a indirect cylinder have two cold feeds?

[WaterTight]

One of which has a gate valve on which turned off the hot but the first I tried (gate valve appeared functional, not spinning) didn't.

Not seen before. Didn't have time to investigate further, was just checking hot could be turned off for a tap change quote.

 

[Leo21]

Secondary return? I've seen it when the hw flow does a loop on gravity and then returns into the bottom of the cylinder.

 

[Ray Stafford]

Are they both definitely cold feeds? Are there two CWS tanks, or do both feeds come from the same tank?

 

[kris]

yeh secondary return , or sometimes a shower connection, when u say 2 cold feeds , do u mean 2 feeds from cwsc ??

 

[WaterTight]

Didn't look in loft, was no need to as could isolate hot with other and give her a price.

I say cold feeds because they both came down in straight to the bottom of the cylinder, drain off, then tapped in. Identical and on opposite sides.

 

[WaterTight]

So is a secondary return to help water keep/stay hotter longer/waste less hot water?

 

[Leo21]

So is a secondary return to help water keep/stay hotter longer/waste less hot water?

Yes, it loops round in the loft to the farthest hot draw off. Meaning when you run a tap it's hot, saving water.

 

[chris watkins]

Traditionally secondary returns are taken back into the cylinder around a 1/4 to 1/3 of the way down from the top as you know but if there is no tapping provided for this & you don't want to fit a Surrey flange it has been common place to take them back into the cold feed.

As some cylinder come with a tapping opposite the C/F to use as a drain off, they might have used it for this. I would expect it to be 15mm & be fitted with a circulator (bronze pump) somewhere if it was.

 

[acecharly]

There would be 2 pumps aswell id say...commercial jobs generally have a hot return pump near the calorifier so id assume the same in a house