2 wire thermostat

[jackel440]

I have a coleman furnace model # 7975c856.when i bought this double wide and had it moved here they installed a new a/c system.worked great,but the problem is we took off the old thermostat since it got broke.all the new fancy(programable) and plain thermostats are not for a 2 wire system and will only run the heater.if you switch to the a/c the a/c will run and not shut off.what are my options.I can't seem to locate a normal 2 wire stat at lowes or menards.
any ideas on my options?
thanks aaron

[Robert]

Hi Aaron,

This may sound a bit confusing, but this is how the 2 wire system works for A/C:

At Furnace, set the two switches to COOL and AUTO.


At T-Stat, set the switch to HEAT .

Then set the temp lever where you want temp in home.




Then for winter Heat, simply change switch at furnace from COOL to HEAT .



Inside T-Stat, hook power wire (usually Red) to R or RH.


Hook Heat wire (usually White) to W.


Always hook wire end clockwise under the screw and be sure screw is on wire, not insulation.


Let us know if this takes care of it. Some t-stats won't work, but most do.


If digital, get one that is battery operated.


Take care and best wishes,
Robert

[jackel440]

Robert thanks for the reply.

I did as you said in the past just switched from heat to cool at the furnace.with the original stat.
with the new electronic digital one.do i just leave it set on the heat or cool switch on the stat its self?I believe it will not control the a/c unit correctly either way.i might just not have a unit that will work correctly with my furnace.
i know i made this as clear as mud
Aaron

[Robert]

Hi Aaron,

Most work, but some do not. No way to know for sure w/o being there.

You would connect the 2 wires to R or RH and the other wire to W.


Set t-stat to HEAT.


Set furnace switches to COOL and AUTO.


Then set temp.


ANY a/c unit will work with any furnace. You have a 2 wire set up and thus, it must be in correct settings to work.


With above settings, it should work fine.


Make sure the t-stat is battery operated also.


Thanks,
Robert

[jackel440]

Robert,
sorry for the long time on an update.I had to get cleaner for the a-coil and clean it.Plus I have been doing Cub Scout meetings.
Well anyway,I got it all back together and set up mt stat the way yu said and it seems to be working correctly.Some reason either me or some one else had switched it to the cool setting instead of leaving it on heat.
Thanks again
Aaron Smith

[Robert]

Hi Aaron,

That's great and you're very welcome.


Take care and best wishes,
Robert