Heat only working when tstat is set way above room temp

[tideman76]

Hello all,  I thought I would return here to get advice on my HVAC system.  You all helped me with washer and dryer repairs in the past. 

Anyway, I have Central Air and Gas Heat.  I believe the unit is a Trane system.  Not sure of the age (definitely up there in years) or size.  It finally got cold enough to use the heat and when first turned on for the season, the heat didn't come on.  I turned power off to everything and then back on.  The furnace then started working, but not reliably in the fact that it seems that you had to turn the setpoint way above room temp to get the heat to finally come on.  I had been wanting to replace the thermostat anyway, so I did.  Granted, I bought a cheap Ritetemp thermostat and installed it.  Anyway, I thought everything was working until I started looking closely. 

Example:  Last night at bedtime, room temp was 68, heat set point was 70.  This morning the room temp was 63 (doesn't appear heat ever came on).  I moved the set point to 78, and within a few minutes the heat then came on.   This is not normal behavior. 

Let me be a sponge for your knowledge. 

kevin

[AccApp]

When the t-stat is left @ 78° does it get to 78°?  Did you set the it for the proper delay for your type of system when you installed it? Sounds like an obvious thermostat problem from what you have reported.

[applianceman18007260692]

you must look on the gas valve and determine what amp draw is has, .1,.2 etc, and then set the new tstat heat temperature advance setting .this is called a heat anticipator  what the heat anticapator does is turn the valve on and off slightly before the room is warm.  it has a little needle setting with the amp draws shown if you are lucky the amp draw will be posted on the gas valve . if not then it will have to be metered with a special amp draw meter