Cylinder thermostat l641 help

[ih]

Hi my system is potterton profile boiler + hw cylinder with l641A1039 cylinder thermostat and Y plan valve +st6400C programmer past few days i suspected water was very hot decided to check stat ( i turned down room stat) i cannot hear any clicks on turning cy stat right down or right up? Does it mean faulty cy stat?
Also with my limited knowledge i thought turning cy stat right up would fire the boiler but this did not happen?
Should this happen? Thanking in advance for help/advise
Ih
Ps programmer was not set to call hw!

 

[ianmcd]

Might be but you will have to check with a multi meter

 

[ih]

Ian thanks for response but being retired is no excuse but am poor with multi meter can do it only
If there is a video! Lol!

 

[ianmcd]

plenty of them on youtube

 

[ianmcd]

your stat couldnt be easier to check, demand for HW at programmer, and you should get live voltage at C at stat, with stat turned up demanding heat you should have live at terminal 1 with the stat turned right down no demand for heat , you should get live at terminal two and nothing at terminal 1. if that is happening then the fault is not with your stat

 

[ih]

Many thanks again will have a go also kindly confirm if room stat down and i put the cy stat right up should
The boiler kick in???
Regards ih

 

[ianmcd]

Many thanks again will have a go also kindly confirm if room stat down and i put the cy stat right up should
The boiler kick in???
Regards ih

set programmer to HW only, then see what happens when you turn the dial on the cyl stat, as long as the cylinder isnt too hot the boiler should go on and off as you turn the cyl stat up and down

 

[ih]

Hi again i did as advised fyi the boiler is not responding to cylinder stat i.e. turning off/ on it is staying on
Servicing hw demand ! Ian di we conclude faulty cy stat?? Thanks 4 your help

 

[ianmcd]

what happens when you put ch only on without the HW, does the valve motor across and stop any water going to the cylinder and fires the boiler for the radiators ?

 

[ih]

I hope i have done it right! The valve motor stays on auto side it did not motor across but the boiler kicked
In and radiators are getting hot!

 

[ih]

Hi i think ian is busy! Any help to close this if cy stat is faulty i can replace
Thanking in advance
Ih

 

[ianmcd]

for all they cost just change it and come back if it doesnt work

 

[ih]

Hi ian just to say many thanks for all the help! It did take me some time as had to be yoyo as all
In loft apart from boiler! My oh will not help as she thinks i will wet/burn the house! But successfully
Used the meter with ur instructions and found with no demand 4 heat i donot get live @T2 also i get
Live @ t1 i hope this helps others once again thanks
Ih

 

[ih]

your stat couldnt be easier to check, demand for HW at programmer, and you should get live voltage at C at stat, with stat turned up demanding heat you should have live at terminal 1 with the stat turned right down no demand for heat , you should get live at terminal two and nothing at terminal 1. if that is happening then the fault is not with your stat
Hi above is advise by ian on possibly faulty cy stat kindly help i have managed to replace the cy stat but with room stat turned right down no heat i get nothing @ terminal 2 and live @ terminal 1 is new stat faulty or is it typo?? (Part one is correct hw demand i get live@ C also with stat turned up demand for heat i get live @ terminal 1) also with hw demand when i turn the
Cy stat down boiler switches off and when turned up it kicks in
Thanking in advance
Ih

 

[ianmcd]

your room stat has absolutely no bearing on anything that the Cyl stat does