gas furnace- what is normal?

Mine did that too, but is a diff model Carrier. Was caused by a slug of water in the draft motor pressure switch tubing.

MikeB

No.

No one here can tell you. Its being cause by something, and it could be as simple as a bad limit, or an improperly set gas valve.

in a working forced air furnace in my basement, the gas burner cycles on and off while the blower sends the warmed up air to the house until the thermostst is satisfied. the main can't usually run 100 percent of the time or the plenum would get overheated. the system is designed or adjusted at fan in and fan out settings to deliver that range of heat to your registers. if your furnace is not operating properly be more specific with the symptom you have.

mike b's post reminded me to tell you that we've cleared up a malfunction more than once, cleaning out the silicone updraft flue blower motor tube connection with a paperclip.

"Mine did that too, but is a diff model Carrier. Was caused by a slug of water in the draft motor pressure switch tubing.

MikeB"

Here is another one, that has a problem, and has no clue he does......

yes..properly INSTALLED units can run 100% of the time like they are designed to, and never shut the gas off till the thermostat is satisfied. If they are not, somethings wrong..

Y'all musta found some funky gas valves lately. This is the second thread you've mentioned it in...

I just wanted to know if gas valve cycling is normal while the thermostst waits to be satisfied. one says no others say yes.??? anyway...i changed a dirty filter and the valve remeined opened during the complete cycle, which leads me to believe... that gas valve cycling ( on my model) is NOT normal.......Thanks for your inputs and discussion. its all helpful.. Bill

Ever seen one with the burn rate set too high? Can cycle the unit in and out and in and out several times over the course of a call for heat.

Well, quite simply...its NOT normal on ANY model made in the last 20 years....or any before that if its installed right. Call for heat from thermostat, valve is open..unless a thermal trips...

Never seen that.

On the newer Yorks, Tranes, and Carriers in particular, if you set the gas valve too high, and dont finalize the heat rise correctly, you can overheat a limit, that will allow the unit to continue to run, but shuts down the valve..since its a self resetting Kilxon, when it cools off, it resets the valve circuit and will fire back up.

I don't start up those brands any more, but I will remember that...

Thanks.