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Sean
Sean, HVAC Technician
Category: HVAC
Satisfied Customers: 131
Experience:  Owner HVAC company
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I had a honeywell t stats go out. bought a new wifi stat.

Customer Question

i had a honeywell t stats go out. bought a new wifi stat. honeywell also. the equiment i have is as follows: trane compressor XR15, Trane furnace heatpump with gas backup XB80 model tue080a948l3. the furnace has five wires to connect to, so i also have a honeywell interface module thm5421c, i guess this is to make the connections work for older furnace unit? the new stat is rth8580wf1007. i need to know if they are compatible, if so i need to know how to wire the stat, the module and the furnace
JA: Thanks. Can you give me any more details about your issue?
Customer: well like what?? that was pretty comprehensive
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Submitted: 8 months ago.
Category: HVAC
Expert:  Sean replied 8 months ago.
Ill check into this and see if I can help
Expert:  Sean replied 8 months ago.

I looked into this, What is full model number THM5421C1008/U ??? is that it?

IF it is, The thermostat you purchased will not work and you will need to get the thermostat that matches that equipment which is TH9421 VisionPRO IAQ Thermostat

How many wires do you have at that the thermostat now?

Customer: replied 8 months ago.
the module just shows thm5421c, i have 5 wires there now, the heat works but only the gas, NOT the heatpump (compressor not coming on)so the module is to connect the newer xr15 compressor to the older furnace i guess. so is there another option besides the module, can it b e bypassed? if not then i guess i have to spend the big bucks on the correct stat. if that is the only option, do you know the wriing diagram then for the module?
Expert:  Sean replied 8 months ago.
Im out for a little while as soon as I get home ill dig into this and we will figure out a solution. It may require some pictures to send to me if you can.
Expert:  Sean replied 8 months ago.

would you like to work on this?

Expert:  Sean replied 8 months ago.

?

Customer: replied 8 months ago.
I called Honeywell, bypassed the module, dont need it, programmed stat, 5 wires ok, air came on. But fan in auto mode stayed on. Need more programming, honeywell has a case number, ill chk more today
Expert:  Sean replied 8 months ago.

Alright ill hold tight if you have any questions ill help ya.

If you wanna try and fix it we can ?

Expert:  Sean replied 8 months ago.

Just wanna touch base with you and see if Honeywell got ya squared away or if you have any questions.

IF you completely changed thermostats i would recommend Sensi if its not too late. Great easy thermostat!

Expert:  Sean replied 8 months ago.

If you can rate our conversation so we can close this out unless you need more help. Rating our conversation is the only way that we get paid for our time otherwise we make nothing for our time.