Gas and Oil Home Heating Furnaces - Changing Thermostats

Hey everyone Im new to the boards. Im having a problem changing the thermostat to a new one. It says to label the wires but how do you tell what wires are what? I dont see any writing on them nor is there any where the screws are that hold the wires. i have a 3 wire thermostat and the wires are Blue, White , Red. Im really stumped. I think the thermostat that i have is pretty old. It is a Flair brand i think. I would appreciate any help Thanx

is this forced air system w/ A/C?

Hot water heat?

Most of the time, Red wire goes to R (24v power), then the white wire goes to W (Heat)... as for the blue, what was it hooked up to on the old t-stat? On some system. blue is C (Common).

But we need to know what you got for a heating/cooling system. and what brand/model is the new t-stat?

Thanx for the response. Its hot water heat. The old stat had no labels or letters to identify it. They just went to 3 screws. They were labeled with a blck marker with the numbers 4,5,6 but im sure that the person who installed that wrote them. The blue one looks like it atached to the screw that goes to the dial. I hope that helps. Thanx again

Tell me what your new t-stat is.. Brand, and model # please..

Do you have a zone system in your home? (more than one t-stat)

I baught a ritetemp 8030c. i got it a home depot. I have only the one thermostat. I hope this isnt the problem but i live in a condo.Would that be the problem with the wiring??

Do you have access to the boiler to see what they hook up to there?

I am trying to get on the web page of rite temp's. and not getting me in..

Look at your install book, should be a drawing showing what wire to hook up where.

I'll post back soon as I get the info on my end.