Lifestyle 679H340-30L0 valve, hot water issue.

[matchaw]

Hi,

I have a 3 way mid position value, Lifestyle 679H340-30L0, it looks to be the old model which doesn't have the black button you can press to remove. On the side of the unit there are markings W M H and below there is a slider which you can move when the unit doesn't have power.

What happens is:
power off = slider moves to W due to the spring.
power on = slider stays put until you select either water or heating on the programmer
select heating = slider moves to H and stays put.
select water whilst heating is on = slider moves to M and stays put.
select water without heating on = slider starts to move gets to M and then starts clicking.

If I feel the pipes which go to the radiators and to the hot water tank I can feel each of them getting hot, but I am unable tell if the valve is working for hot water only as the slider will not move to the W position.

I have already replaced the motor and this didn't solve the problem, so does anyone have any ideas, before I need to replace the entire thing!

Thanks
Matt

 

[Agile]

I am not 100% convinced but it sounds as if the gears are slipping. But your valve is quite old now.

Apart from the Honeywell many of these valves are not as well built as one would hope!

Tony

 

[matchaw]

Hi Agile,

But I have just replaced the motor, is there any more gears? It still makes a clicking sound when trying to do hot water only, It sounds like the micro switch it clicking, but the boiler still fires etc.

The actual value does move because I can have heating only and this does not heat the hot water tank, but when selecting water only, this then moves to the 'M' position and heats my radiators also.

 

[D_Hailsham]

What happens is:
power off = slider moves to W due to the spring.
power on = slider stays put until you select either water or heating on the programmer
select heating = slider moves to H and stays put.
select water whilst heating is on = slider moves to M and stays put.

That's normal behaviour.

select water without heating on = slider starts to move gets to M and then starts clicking.

If you have heating off and turn the hot water on the valve should not move to M; it should stay a W.

If the valve is trying to move to M, it means that it is receiving a call for heating. Faulty programmer, or room stat or motorized valve.

I am unable tell if the valve is working for hot water only as the slider will not move to the W position.

Can you explain more fully when this happens.

If you want to have a go, there are complete fault finding instructions in How a mid-position valve works

 

[matchaw]

When I select hot water only, it does not stay in the W position, it moves to M. I have changed the motor already and this is still the same behaviour.

What I've done is switch on the heating and I can feel just the radiator pipes getting warm, the pipes leading to the tank are cold. Then If I switch the programmer to hot water and heating then I can instantly feeling the pipes to the tank get hot as the slider moves to 'M', so I know the valve physically opens.

I cannot test if the valve is opening *just* for hot water as when I switch on only hot water it always moves to the 'M' position.

 

[D_Hailsham]

Please read the link I gave in my last post. It explains how the valve works.

The diagnostic tests given will determine where the fault lies and remove any guesswork.