TRV as cylinder stat?

[Axel]

Has anyone ever seen a TRV located on the heating circuit feed into the HW cylinder, adjacent to the cylinder, being used as a cylinder stat?

 

[gas4you]

What you are descibing sounds like a Drayton Tap Stat. It will have a sensor fitted to the HW cylinder that is attached to the stat by a small copper wire.

It is not a TRV

 

[Axel]

Might well be a wire in there - bit dark and pokey in that cupboard. Looks remarkably like one of their TRV's; but I guess it's a good way to make a product have multi uses.

Thanks

 

[JohnD]

they are used if you have a Gravity feed to the HW cylinder. Take care of it, they are very expensive (round about £100).

The "wire" is actually a very thin tube with a thermostatic pressure vial on the end, which is (should be) strapped to the cylinder. You can adjust the temp of the hot water with the adjusting knob on the valve.

It is very important not to cut or damage the tube.

 

[Axel]

Ok, thanks. Now I understand why it is there. I won't go near it, as it's all working at the moment (You know how it is as a plumber - you walk into a room and anything you stand near to chooses to fail...!)