Hot water cylinder valve

londondulwich

We have a condensing gas boiler which heats our hot water and radiators.

There is a copper tube leading from the cylinder with a red valve at the end (USV16/22). The valve has numbering running from 0-7.

At the moment it is set to 2.

Does anyone know what the ideal setting is?

ormus

what cylinder? and where is the valve exactly?

londondulwich

Thanks for replying.

I should've said the hot water cylinder (HWC).

The valve is fitted to a loop which runs from the boiler to the HWC.

It controls the flow of water coming from the boiler to the HWC. The tighter it is, the more difficult it becomes for the water to return. If the valve is very open the hot water has little to encourage it into the HWC and so goes back to the boiler.

My concern is that if the valve is too open, the boiler will be working unnecessarily.

If the valve is set 0 no water can return, which would probably dangerous. If I open it up full, to number 7, hardly any of the hot water will get into the cylinder.

Does anyone know the best number?

mattogier

Hi

Firstly it should NEVER be dangerous to shut off this valve - all will happen is that the hot water cylinder will not heat up.

You should, I think, treat it the same as the lockshield valves on your radiators - it is for balancing the the flow (an hence heat) to a particular rad or tank.

I will assume that there is an electrical valve that shuts off supply to the hot water tank when it reaches a certain temp or when the controller tells it not to heat water.

If you set the valve in question to full open then you will find that the hot water heats up before the radiators (as it is closer to the boiler and hence less friction water will want to go the easiest route) - when the hot water reaches temp then it should shut of this loop and divert all the boiler hot to the radiators.

If the valve is fully closed then the hot water will never heat up BUT you will have toasty warm rads when the system is on.

Infinetly variable between!

If you want to balance the system correctly you will need to get a couple of thermometers that you can strap to the in and out of each device (RAD or HWT) and adjust the system until you have the desired temp drop across the device (20 degrees C?) - consult a plumber or google for more info.

Canucklehead

Hi

The setting should be the one you found it at. Turn it back to where it was and leave well alone
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Corgi Guy.