changing a cylinder thermostat

[AllenP]

the thermostat on my hot water cylinder needs changing - having just bought the new one I find the wiring is different. The cabling I have connected to and old ACL HTS 2 is red, yellow and black - the new one a Sunvic shows in the diagram - yellow = call for heat., White = satisfied, and Blue = common.

Judging by the way its laid out I think the red cable would go to white/ satisfied the yellow to yellow / call for heat and the black to blue / common - but I would welcome any advice

 

[seco services]

test them with a multi meter.

 

[aGasMan]

If you have a multi meter put it on resistance (ohms) attach the probes to two of the three spades. and adjust the temperature on the stat. if you do not get continuity (the expected reading would be OL) then the one you have not attached your probes to is common.

Then attach one probe to common and one to another, now adjust the temperature if you get continuity on low then this is satisfied. If get continuity on high then it is calling. (Note that low and high depends on the temperature listen for the audible click to see wether it is high or low).

 

[AllenP]

Thanks............now sorted