Synch motor fault not opening

[James f]

Hi I have an issue, couple of day ago no water. Boiler worked ol for heating so looked at syncho motor ( had to replace this about 5 years ago on the same system). Motor was working but when I checked it it was not opening the water valve enough to actually make the contact switch to tell the boiler to fire. I replaced the motor and all ok....2 days later I now have the same fault. Even when I use the lever and open the value it is not opening far enough to 'click'the microswitch and fire the boiler...anyone have any thoughts?
The pic shows me fully opening the lever to manual mode and you can see the gap to the microswitch.

 

[Burger]

Probably a dirty system and sludge preventing it. Or it might just need a new head? When you move the lever is there a strong resistance?

 

[James f]

Hi yes there is resistance

 

[Harvest Fields]

How old is the valve?

 

[James f]

The house is 15 years old. I've been here for 8 years and I've not ever replaced it.

 

[Harvest Fields]

If you are confident enough with electrics you could try and change the head yourself. But make sure the correct checks are completed first as it may be something else. If not get a gas safe engineer in to repair it for you.

 

[James f]

Thanks..

 

[Harvest Fields]

Thanks..

You’re welcome mate.

 

[Burger]

Just for information purposes, it doesn’t have to be a gas safe registered engineer to replace your motorised valve head. As Harvest said, if you’re confident enough you could do it yourself. One thing you might want to check with the head off is the valve spindle.

 

[James f]

Yes I'm happy to replace the head.
However, I'm now more confused. I came home just now and the boiler is running but the program timer is not set for the boiler to be on. Went upstairs and would the hot water motor valve working and fully open, hence has switched the boiler on. To my understanding the sync motor is AC current so can be wired in either way round?

 

[Burger]

Went upstairs and would the hot water motor valve working and fully open, hence has switched the boiler on. To my understanding the sync motor is AC current so can be wired in either way round?

Motor can be wired either way as it’s AC. Yes iirc if it’s stuck on the microswitch then sending a signal to keep boiler and pump running.

 

[firemant]

Even when I use the lever and open the value it is not opening far enough to 'click'the microswitch and fire the boiler...anyone have any thoughts?


View attachment 39666

It won’t. Manually opening the valve DOES NOT close the MS. It leaves the valve open.

 

[firemant]

Yes I'm happy to replace the head

Has the head cover got a dimple?

 

[Burger]

Has the head cover got a dimple?

If not, take and send us a photo of said valve

 

[James f]

Yes it has.
At the moment the sync motor seems to have a mind of it's own. The hot water is coming on a various times WITHOUT the timer program asking it to. When I do try and turn the timer on the boiler doesn't fire and upstairs the sync motor isn't doing anything....

 

[firemant]

Feel the pipes immediately coming off the boiler, when the boiler NOT firing. If they are hot, it may be that the HW MS is stuck ON. When cool enough, the boiler will heat, but not circulate (no bypass?), ten sht off pretty quickly on the boiler stat.