Suburban Furnace Problem

[Riverc]

My furnace in not working right.It will work 2 or 3 times fine.Then it comes on sail switch clicks blows hot air during that cycle I hear the sail switch click 2 times the furnace shuts down and will not come back on at preset temp.I have to shut on off switch at thermostat for it to work again.

 

[Great Horned Owl]

If the sail switch is clicking on and off, you are not getting enough air flow.

One possible cause is mechanical, either a pinched duct, or some kind of obstruction.

A second possibility is that the blower motor is going bad, or the blower is loose on the motor shaft.

A third possibility is low voltage to the blower motor. It might be caused by the atteries not being fully charged, or a bad connection someplace in the circuit.

A fourth possibility is a bad control board.

Joel

 

[Alfa38User]

In many cases I would be surprised if you can hear a sail switch operating but by careful listening, what you more often will hear is the igniter clicking (3 times max) while trying to light the burner. After three attempts to light (3 clicks) and a failure to light, the furnace will be locked out, the fan will continue to run a bit to clear out any un-burned fuel and then shut down. To reset a furnace you have to shut down the request for heat using the thermostat before attempting to light it again. I wonder if yours is cycling or shutting down by the overheat switch, since it seems to work ok for 2/3 attempts???

If the sail switch is not operating, there is a lack of sufficient airflow as was mentioned above. Check the air passage (combustion air from the outside) for potential blockage such as mud wasp nests etc. The gas valve will not be permitted to open nor will the igniter click. Do you detect any propane odor at the exhaust outlet when this clicking occurs?? This will help to tell you at what point the failure is occurring.

 

[Riverc]

Have a tech to check the problem.Will update when fixed what the problem was thanks for the help guys.

 

[Riverc]

Well took Furnace to shop for a bench test.Got the call tech said everything was good.
Put it back in it did the same thing.Pulled it again checked the flame sensor it looked bad thought that had to be the problem put a new one in,wrong.
Pulled it again changed the Gas Valve it's running good,hope that's the fix.