I changed the thermostat and didn't find any change. Its worst when the outside temp is lower and I need the heat most. I've forced heating gas furnace. Please help me what could be the problem.
basically, the part on the furnace that the thermostat is connected to is faulty. they burn out occasionally
The thermostat has an adjustment for the way close it particularly is going to stay to the setpoint. frequently that's desperate to overshoot the temp with the help of two tiers, and not turn the warmth returned on until eventually it drops 2 tiers below the setpoint (noted as the administration zone). sounds like your thermostat is previous and probably choose replaced. I had this comparable situation some years returned, and a clean Tstat fastened it.
have you checked the amp's yet ? lol no really the unit is prob having age issues you might try a unit wrap keeps the heat in the unit when cold out to help get inside,