[sarahleedavid]

Errr what if both wires are red?

[nickh123]

Hi, I have an old 2 wire Taco analog thermostat and want to upgrade to a digital thermostat. The wires are white and blue (the red wire is cut and not connected to anything) and neither terminal is labelled. Any suggestions on how to wire new device?

Thanks

[Grady White]

Connect one wire to Rh & the other to W on the stat. Use a battery powered stat.

[DaveG72]

Is it just me, or did NO ONE answer the question on how to hook up a 2 wire setup to a digital (no battery) thermostat; which I thought was the original question?

Yes, 2 wire = Rh+W great... what about hooking in a WiFi digital thermostat? Feasible or not? And if yes, how? (regardless of wire colors which can't be relied on)

Any suggestion would be very welcome. Thanks.

[elecman]

Thank u it worked very well..

[elecman]

Thank u for your asvice. It worked very well and I'm very happy. Hoping it will help with my power bill..

[elecman]

thank u for your asvice. it worked very well and im very happy. hoping it will help with my power bill..

...

[somewhat345]

We are trying to replace an old school thermostat with a Honeywell 5-2 programmable thermostat. When we took off the old one, the wire we have are as followed: romax with red/white and another set of romax that has no colors. When we connect all the wire as we think, it causes the furnace to run. When we switch it to A/C, every thing works. Can you tell us how to hook it up?

[JoseLuis14]

It Didn't Work, one of the Wires was feeding off another to serve as a C wire, I called HoneyWell and they said their updated wireless thermostats will not work with my two/3 wire system unless I have an entirely independent C wire running from the heater -_-

[tattoo1255]

Buying a home with an interlink furnace. Pilot will light but burner will not ignite. There has been no gas in the home for over a year. Line was purged, pilot lit, thermocoupler kept pilot lit. However the main burner won't light. Supposedly the furnace worked in Sept. 2012 when gas company came out and lit pilot. HELP!

[Grady White]

Tattoo:
Are you sure the gas valve is set to "on" & not "pilot"?

[tattoo1255]

Yes. The gas valve was set to on after lighting the pilot. I am assuming you are talking about the knob on the gas valve that controls the pilot and burners. Atl Gas was trying to light it and I attempted to as well after he left. Same result, pilot lights and stays lit. Turn the knob the rest of the way and nothing happens. This was with the thermostat turned to 90 degrees, house was about 60, fan in auto and switch set to heat. Tried the cool side of the thermostat thinking it may have been wired backwards but to no avail.

[Grady White]

Ok, you've covered some of the common mistakes.
If you have a voltmeter & know how to use it, measure voltage at the thermostat. You should get +/- 24 volts AC between terminals R & W. If you do, put the stat back on, set it for heat & turn it up high. Measure voltage between R & W at the furnace. You should get nearly nothing.

[mcanseco]

My new one has batteries as well, and no W1 or RH. It does however have a R and W hookup. Hopefully I get this thing to work, it's starting to get a little chilly in the AM...

[mommynkiddos]

Im replacing my old honeywell round thermostat (with Mercury) both wires are the same color... What do I do??

[Grady White]

mommynkiddos: hook one wire to 'W' & the other R. It makes no difference which is which.

[dbird]

This may be the wrong place to ask, if so I apologize, but, with new wiring and an appropriate relay, can one convert a mobile home style gas furnace, with the heat/cool switch on the blower, to work with a newer stat? I don't mind running new wires or setting up a transformer inline if needed, but do not want to spend what I was quoted on a new furnace.