Trying to Wire a Second Thermostat to My Furnace Blower...

titleist1 · Post by **titleist1** » Fri. Dec. 10, 2010 11:02 am

Bratkinson wrote:One suggestion...attach a note to the thermostat and to the coal stove as a reminder to put the jumper back to the original position when shutting down next spring.

I am thinking I don't have to set the jumper back to where it was. As long as the AC operation is not affected by this jumper when in COOL mode (the manual indicates it won't) the heating function is working as it should with the proper fan delays if the furnace does activate. I will have to test out the COOL mode with the jumper as it is now set to see if it really does not cause an issue.

AA130FIREMAN · Post by **AA130FIREMAN** » Fri. Dec. 10, 2010 4:13 pm

Insteat or removing the jumper (if it is needed) add an external switch.

Rogerd · Post by **Rogerd** » Mon. May. 04, 2015 10:09 am

Where did you purchase a two wire thermostat?

McGiever · Post by **McGiever** » Mon. May. 04, 2015 12:28 pm

Rogerd wrote:Where did you purchase a two wire thermostat?

Not sure where you are headed with this, but any ordinary thermostat will work as a 2 wire thermostat even though it can have 7-8 connection points.

Simply use only which connections you need...use R & W for heating only.
Only thing you will for sure need is a thermostat which uses a battery if it has a digital display when used with 2 wire, because a 3rd wire is needed for the display otherwise.

Rogerd · Post by **Rogerd** » Mon. May. 04, 2015 8:46 pm

I want to use a second thermostat to shut off the a/c compressor at a certain temp. The compressor will shut off at a higher temp than the primary thermostat. I'm not sure how to do this. Any suggestions?

McGiever · Post by **McGiever** » Mon. May. 04, 2015 10:19 pm

Rogerd wrote:I want to use a second thermostat to shut off the a/c compressor at a certain temp. The compressor will shut off at a higher temp than the primary thermostat. I'm not sure how to do this. Any suggestions?

You will want to use the R&Y thermostat connections for cooling, and then control a 24 volt 2 pole normally open relay to switch on and off the compressor motor.

Rogerd · Post by **Rogerd** » Tue. May. 05, 2015 9:33 am

I was thinking I could just connect the yellow wire to the second thermostat and set the temp and it would shut the compressor off when the second thermostat temp. was satisfied. Why will that not work?
Thanks
Roger

McGiever · Post by **McGiever** » Tue. May. 05, 2015 10:54 am

Rogerd wrote:I was thinking I could just connect the yellow wire to the second thermostat and set the temp and it would shut the compressor off when the second thermostat temp. was satisfied. Why will that not work?
Thanks
Roger

It can work...assumed you wanted to do this all with the 2 wires only.

If you have a yellow you must have 5 or more wires.