Sticking motorised valve

[Minmin]

Hi,

We have a lifestyle 679H340-30L0 motorised valve which we think we are having problems with it sticking.

The heating only does not come on when on timer sometimes (lever stays in the central combined position) after both heating and hot water have been on on timer, especially if the hot water has been advanced at some point.

We have worked out if we turn off the heating, advance the hot water, then advance the heating whilst the hot water is still on then turn off the hot water, allowing a few seconds in between each stage, the heating only works.

Is this a sticky valve or is it more of a circuit issue?

Thank you for your advice.

 

[Hugh Jaleak]

If it worked ok before and no-one has touched the wiring then likely to be a dodgy valve, they only have a certain lifespan. Its possible to just replace the head without draining the system on some valves, provided valve itself moves freely.