I have an older Lennox A/C - heating system with a Lennox 21J7101 thermostat. We noticed the past couple of days that the blower fan will try to start for about 1/4 to 1/2 second (really quick) and then stop. The thermostat was in the HEAT position at the time. We placed the thermostat in the OFF position (has COOL / OFF / HEAT positions) and it still continues to happen at irregular intervals. I have moved the temperature adjustment to both the hottest and coldest positions, but the problem continues.

It is hard to get someone to look at it as there is no way to know when it will happen next. Sometimes it takes hours to happen again, and sometimes it happens multiple times in 15 minutes.

HELP!!

Replace lennox with a good furnace

replace lennox with a good furnace

Sure. Send me the money and I will. Now, is there anyone with any HELPFUL responses?

Just giving you a hard time.

Is it draft inducer motor that starts and stops, or the blower motor that starts and stops?

I feel for you. Its hard to fix an intermittent problem.

Other than this problem, does the furnace work(keep the house warm).

replace lennox with a good furnace

Just make sure it isn't a Trane :p

Lol, or a carrier