Changing Motorised valve

[Simon123]

The 3 position motorised valve has packed up on my Sundial Y Plan system. I have purchased a new valve to replace the old one. Does anyone know whether I have to drain down the whole CH system to swap the valve? The valve is located next to the HW tank in the upstairs airing cupboard. There is an isolation valve between the pump and the motorised valve.

 

[Agile]

Gererally you will need to drain down to a level below the valve.

Depending on the fault its sometimes only necessary to change the head which can often be done without draining.

Tony

 

[Simon123]

Thanks for the speedy reply. Pardon my ignorance but I assume that the powerhead is the silver box that is attached to the 3 way valve?

 

[Simon123]

Could the problem be with the motor within the powerhead? Is there an easy way to isolate the faulty component?

 

[semi-acoustic]

You are better off replacing the whole thing, providing you have easy access to the valve, you need to isolate the power supply first.
If your valve is a Honeywell, and there is a raised lump on the top of your valve, (near the power chord) then it does not need a drain down, if it is completely flat then you will almost certainly need to drain down.
Remember to write down or label any wiring you disconnect as there are quite a few, I do not wish to be patronising but I have made that mistake myself.

Good Luck

ps If your valve is not a honeywell, then contact the supplier or a good engineer.

 

[Agile]

The motor could well have failed.

You can measure its resistance and if its open circuit then its failed. Should be about 2K. Might also have seized up.

Its quite easy to change if you dont lose the tiny screws.

A magnetic screwdriver helps and a professional would spread out a sheet underneath just in case ( and have spare screws salvaged off old units. )

Tony