We have an older Empire Heating Systems wall furnace. We would like to replace the thermostat with a Wyze thermostat. There are only 2 wires in the back - red and white. There is a single yellow wire in the front. I am attaching pictures for reference. Can we make it work?
Without knowing a model number, I am only guessing.
This might be a 24 volt system. Can the thermostat be removed to check for a model number?
Some older systems don’t require voltage. A device is placed in the flame, and this creates voltage which is routed to the bimetallic thermostat.
It is a 24v thermostat. Here are some other pictures. (only let’s me do 1 picture at a time)
I don’t own the Wyze thermostat, but my limited knowledge says it will work. You will need a jumper for the C wire.
Perhaps someone more knowledgeable than I can verify my theory.
Oh, even though this is low voltage, a wire should always be wrapped clockwise so,when tightening the screw, the wire gets wrapped tighter. This is backward, so tightening the screw unwinds the loop.
This is better, but the contact point is minimal. The wire needs to be looped. At least this one is going in the right direction.
Looking through the manual for this brand of furnace, I see that these are millivolt systems. The wyze thermostat doesn’t have an isolated output, so you would want a C adapter transformer to power the wyze and an isolation relay to protect your thermopile from the 24vac.
Here is another picture of the thermostat. Not sure if 9916E2 is a model number or serial number. There is a sticker on the cover that says - TYPE 1C20-16. The model of the furnace is Empire FAW-55SPP.
What @speadie said… I have no experience with millivolt systems.
So, this one’s not a millivolt system. Not sure if the furnace’s transformer is powerful enough to run the wyze directly, but at least you wouldn’t need an isolation relay.
Easiest way to wire it would be to pick up a plug in C transformer and connect it to Rc and C, then connect the wires from the furnace to Rh and W1.
Tell the wyze your “old thermostat” has the following wires: Rh, Rc, W1, C
Polarity doesn’t matter, as long as the C transformer is connected to Rc and C and the 2 wires from the existing thermostat are connected to Rh and W1
Thank you much! Sounds like I have a plan.
Thank you much!