My old programmable thermostat got fried on Jan 1 with no stores openned. Managed to find a UPM THM303M thermostat.
We AC and gas furnace with blower. 4 wires coming out of thermo: red, green, white, black.
Prior thermo had red to R, green to G, white to W and I believe black to Y but not 100 % certain.
Installed same layout to new thermo but now blower stays on indefinitely when fan set to auto. When I switch the Cool / Heat switch to the off position, the blower will stop but I don't want the blower/fan on one the furnace stops.
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Is this a Heating only Unit/Furnace? It sounds like it is. Usually Red or Black would go to the R terminal
and the White wire would go to W terminal. You will
not have control of the blower motor it will only cycle
on in the heat mode.
I would probably run a new four wire to the thermostat so you could turn the fan on in the on
It depends on the type of thermostat you have.
Do you have a 4 wire or 5 wire T'stat? The red jumper wire was for a 5 wire t'stat with 1 transformer, the red jumper actually should have been from R to 1. So you need to trace the wires back to the furnace and make sure they go to the locations identified below. if you have a 4 wire t'stat then you don't need that jumper, if you have a 5 wire t'stat then you do need that jumper but it should go from Rh to Rc.
4 Wire Termostat
R = Red One Side of 24 volt Transformer
G = Green Blower
Y = Yellow Cool
W = White Heat
5 Wire Thermostat
with one transformer for both units
Rc One Side of 24 volt Transformer
Rh Jumper Rc to Rh
G = Green Blower
Y = Yellow Cool
W = White Heat t'stat?
Two wire hookup on the old thermostat tells me that it was set up for heating only. You will most likely need a modern thermostat. But in the meantime try this with the old one. The two red wires on the furnace are probably Rh & Rc. If so these can be put "together" on the R terminal on the old stat. The two W's on the new furnace are probably W1 &v W2 This is for first and second stage heat. You can put the two "together" on the W terminal on the old stat. Do not hook up the greens (blower fan wires). Do not hook up the blue wires (They would go to the Y terminal on a modern stat for airconditioning.
Who ever sold you the furnace should have offered you a new thermostat.
sounds like you have a heat pump the w2 on old thermostat is for a second stage heat. If you can give me a little more information on type of system you have (forced air furnace with heat/cool, Heat pump or boiler)? How many wires are on old thermostat? Is it a no programmable or programmable? How old is the furnace?
Does the furnace burners light? You could have a bad thermostat or a flame sensor. To check if it is thermostat turn power off to furnace take thermostat off wall take wires marked r & w and connect them together then turn power back on. If furnace comes on and stays on then you need a new themostat if not it is the flame sensor inside furnace. Also check furnace filter
To get the fan to work, look at the heating system to see what termoinal the blue wire is connected to. It should be the "G" terminal. If so, connect the blue wire to the "G" terminal on the thermostat and then manualy switch the thermostat to "Fan On". Indicate what terminals you have on your new thermonsta ie "G" "R" "Y" "C" "W" etc... For a fan to work, typically you connect "R" to "G" on the furnace.
The clicking noise is a relay or switch of some sort. You are right about that. I have 2 questions. 1) does the thermostat have a mercury bulb in it? 2) when the fan shuts off and on, does the burner stay on?