furnace won't always kick on?

Question

we have a bryant furnace that has given us problems since we moved into this house 6 years ago.It is about 10 years old, and is practically re-built. We have to turn the thermostat on and off 4 or 5 times then it will finally kick on.We have spent alot of money on heating and cooling companies comming and replacing parts only to have this problem persist. We just had a guy come two days ago and said it just needs cleaned, so for $80.00 dollars he cleaned it and we put in a clean filter, and it kicked on and off good up untill about an hour ago. Now it won't come on even with turning it on and off!!! HELP

Answer 1

Did the technican that came to your house clean the Flame sensor/rod. Alot of companies forget or don;t know to clean this part.

The Flame sensor is a saftey device in the furnace. It looks like a small metal rod that sits in front of the flame. When this rod gets dirty it can no longer sense that there is a flame present when trying to start so inturn it will shut off teh gas. The furnace will do this several times to see if the furnace will light. If it is unsuccessful the furnace will shut down completely.

To restart the furnace you must remove the power from the furnace by means of a switch located next to the furnace or the circuit breaker for the furnace. After you do this turn the power back on and see if the system will come back on.

To fix this problem you must have teh sensor cleaned correctly.

Some other things that could be wrong with your system is that one of the many saftey overloads on your system could be triping. It is very hard to tell exactly what the problem is with out being there to see.

Another hint that you may want to try is to try and see if your system has any type of indicator lights. These lights will tell you in general what the system is doing. It is sorta like a check engine light in your car. These lights can usally be seen in the lower half of the furnace thru a small peep hole. The light will give you a certain number flashed code that you can match up with a code chart some where on the furnace.

Answer 2

I think what Josh is talking about is the thermocouple. He is partly right and since you gave me a hint (getting the furnace cleaned) the guy may have bumped this or moved it inadvertently. It should be about half way into the flame of the pilot. The other problem could be the thermostat.

I don't know what you can do. Go to home depot with the picture or a drawing of the thermostat. You have to be accurate, they're expensive. There should be numbers on it if you pop the cover off or?
Have another guy, preferably someone that knows what they're doing do this for you. It might be better. Tell him about the cleaning guy and the thermostat. I would bet this is the problem.
If you know what a thermocouple is go down and check it, wriggle it, if it moves, it shouldn't.

Answer 3

Sometimes it takes several seconds or a few minutes to "kick in" depending on the unit, and temperature. You may also need a thermostat.