Worcester Greenstar 24

[fattony]

Hi

I have the greenstar boiler and suspect the zone valve is faulty but I'm not a heating engineer and would appreciate your advice.

The burner is not firing when I call for heat but it does when I call for hot water, this in my opinion rules out the boiler itself, I can test the programmer and room stat fairly easily (I'm an electrician) but my initial thoughts are its likely to be the valve.

If it is the valve do you replace the whole thing or just the electrical side, I'm unsure about draining the system to replace the whole valve, changing it is straight forward.

For information on the valve there is no resistance on the manual lever indicating the valve is open?

I appreciate your thoughts, I have a 3 day old baby in the house, and need to get this fixed tomorrow either by myself or getting someone out

Thanks

 

[petit_pablo]

Check the valve is getting power from the room stat, 240vac on the brown wire. There should be perm 240vac on the grey to valve. When the valve is open there should be 240vac on the orange too.

Depnds what type of valve it is as to whether you can just change the motorhead or if the whole valve will need changing.

Depending on space and pipework layout, zone valves can be a pain in the ass to change or a simple one in one out job.

 

[fattony]

Just a thought, could a low pressure prevent the system from firing, what is would you expect the pressure to be for 8 radiators?

Thanks

 

[dcawkwell]

Use the latch on the zone valves. Open them both and latch.
The switch the hot water on. You will have central heating.

 

[fattony]

thanks, I tried that initially but couldnt move it past a certain point, like it was seized but gave it a bit more force and it went, I only see the 1 3 way valve is that right?

This is now in the manual position and the heating and hot water is on

 

[petit_pablo]

Oh its a mid position valve

Ignore my previous ramblings then!

 

[fattony]

Sorry poor terminology

 

[fattony]

Hi

I changed the motorised valve yesterday, the hot water was working fine and got heat into the radiators by putting the valve in manual, now I have the problem where the boiler will not fire if the hot water is on. If heating and hot water is on together the boiler does not fire.

When i Call for hot water, I hear the motorised valve move and 230v gets applied to C on cylinder stat, 230v on the grey wire (hot water off) drops to 60v but boiler will not fire for hot water.

Everything looks fine but something isn't right any ideas?

 

[fattony]

Could it be a faulty valve head, should I change the entire valve?