I would like to hook up the WTHERM thermostat to an old simple two wire mercury system. I need to know which two terminals would support the on/off function based on the temperature setting.
Then I also need to know how to power the device. I intend to purchase a 24 volt transformer which will have two wires for power. Where should those leads be connected?
The thermostat itself has a total of 10 terminals available. It has an upper bank with Rc, Y1, Y2, o/b and G.
The lower bank is Rh, W1, W2, * and C.
I should think I only need to know which four terminals to use, and maybe the G (Ground).
Can anyone help? I have tried to find a real service manual, but have only found installation guides that assume newer labeled systems being replaced.
C is common (sometimes grounded depending on the transformer), G is fan. - connecting G to ground will blow fuses, so don’t do that.
If your device is for heating, and can take voltage being applied to it, then you can connect the leads to Rh and W1. Tell the wyze that your “old thermostat” has the following wires in this case: Rc, C, Rh, W1.
If it cannot, for instance a millivolt system or an aquastat, you will need to add an isolation relay, wired as shown in this post: