Thermostat wiring for central air...

 We are in the process of adding central air to our house.  The one
thing we might have a problem with is wiring the thermostat.  I noticed
that we only have 3 wires coming up to our thermo.   I've been told
that you can use 3 wires but I am not sure if it's possible.

Can anyone tell me if it is possible to use only 3 wires and how???


Thanks!!   :)



Rich

 

rich@talkandmore.net wrote:

central air system. If you plan on useing elect back up heat you need 4 and if
your going with a heat pump you need atleast 5 most times 6 wires. When ever I
install a new system for someone I almost always run a new T-Stat wire to the
thermostat. Hope thai helps. Steve

 Thanks,

It is nearly impossible to run a new wire here so 3 will have to
do.....

We just need heat and cooling..

Thanks again Steve,

Rich

 Nothing is impossible if you throw enough money and labor at it, it just
becomes difficult.

 
Go wireless.

http://www.programmable-thermostat.com/honeywell/t8665a-wireless-thermostat.htm

P.S. Your professional HVAC contractor should be able to cut you a break
on these prices.