No hot water - thermostat on water cylinder clicking - third replacenent valve!

[BigBurd]

It is an Esi zone valve not Honeywell, usually quite reliable to be honest.

OP what do you mean by cylinder thermostat "Clicking" do you mean it clicks when the temp is switching on and off, or clicking all the time ?

Its clicking on and off - or at least it was before it stopped working

 

[Johntheo5]

Turn the setting knob on the cylinder stat up and down, there should be - 8/10C difference between clicking on & off.

 

[BigBurd]

Turn the setting knob on the cylinder stat up and down, there should be - 8/10C difference between clicking on & off.

We have replaced the ESI zone valve but the thermostat is clicking back and forward every 2 seconds. Is the thermostat the issue?

 

[ianmcd]

We have replaced the ESI zone valve but the thermostat is clicking back and forward every 2 seconds. Is the thermostat the issue?

yes most likely

 

[Johntheo5]

Certainly looks that way, if you turn the setting to max at say 90C does the cylinder zone valve open, anyone who changed the zone valve should have access to a multimeter, very easy to test cylinder star then.

 

[BigBurd]

I've ordered a new thermostat..electrician coming wed. Is it ok to run the system in the meantime or will it wreck the zone valve? Thank you

 

[dilalio]

I've ordered a new thermostat..electrician coming wed. Is it ok to run the system in the meantime or will it wreck the zone valve? Thank you

Run the system? For hot water?
You could, the O/H stat should act as secondary defense but would be better to use the immersion.

 

[BigBurd]

Certainly looks that way, if you turn the setting to max at say 90C does the cylinder zone valve open, anyone who changed the zone valve should have access to a multimeter, very easy to test cylinder star then.

Nope it doesnt move. I've ordered a new thermostat. This will be our 3rd one in 2.5 years and our 4th zone valve though. ESI fitted and being replaced with ESI. Advice?

 

[BigBurd]

Nope it doesnt move. I've ordered a new thermostat. This will be our 3rd one in 2.5 years and our 4th zone valve though. ESI fitted and being replaced with ESI. Advice?

 

[BigBurd]

We've bought a Honeywell thermostat but are confused about how to wire this. The ESI thermostat cable connection has 4 wires but the Honeywell controller is designed to take 3.
I've attached a pic. Can anyone help with this? Thank you v much

 

[Deleted member 267285]

It would help if you said which Honeywell thermostat you’re trying to install.

 

[BigBurd]

Sorry good point! Its an L641A. Thank you

 

[Deleted member 267285]

Sorry good point! Its an L641A. Thank you

That cylinder thermostat isn’t suitable for your unvented cylinder.

 

[BigBurd]

Ah. What model can we use? Any idea? Thank you

 

[Deleted member 267285]

I haven’t worked on unvented cylinders before so there’s none I can recommend, but do an internet search for unvented cylinder thermostat and see the results. I’m not au fait with the rules, but some work on unvented cylinders must be performed by a G3 registered engineer.