I have a brand new gas furnace. It works well for a few days after it is installed. But after a few days the induced draft blower start immediately after the blower off (even the thermostat is satisfied) and the induced draft blower keep on and off very frequently (1-2 times/second). The technician can not know what is wrong with the furnace. When we try to change the thermostat just one thermostat (honeywell) can make the furnace work properly but other three thermostats (including the old one that it work well when the furnace was installed) have the same problem and those thermostats work very well with other furnace and one of them is brand new thermostat. Any problem? Please help!!!!!

hvac1000

If there is a service person there hopefully they will be able to figure it out.

labman

An easy way to sort out furnace/thermostat problems is to disconnect the thermostat. Run a heat cycle by connecting the red and white wires. Likely when you disconnect them, you will still have the same problem as when the thermostat shuts the heat off. Does the furnace flash a trouble code?