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captjack 01-19-2007 11:27 AM

blower runs, with no heat
 
Every couple of days, my comfortmaker hi-efficient furnace continues to run the blower, even though the flame is off. cold air continues to come from the registers till I go down and cut the power to the furnace. Once I turn it back on, the computer does its self check, and furnace runs as it should for a couple of days. I am not refering to the induction blower, but the large blower that pushes the air through out the home. Anyone have an idea why this is happening and how to correct the problem? I would hate to be gone for a couple of days and not have heat in the home.

Thanks

#CARRIERMAN 01-19-2007 11:58 AM

Hi captjack

If you are comfortable working on your furnace. Shut the power off to it or unplug it, whichever is available. Remove the burner door, pull and clean the burners with a wire brush blow the out with compressed air afterwards. Pull and clean the flame sensor rod with steel wool or a wire brush. Reinstall all the burners, make sure that you do not turn the air shutters at the end of the burners while dismateling and reasembleing. Vacuum out the burner chamber while you have it open with a shop vac. Reinstall the flame sensor and burner door. Power the unit back up and see if you have any more problems. If you do let us know what the furnace is doing and we will go from there.

Good luck
Rusty

Furnace_dude 01-19-2007 03:39 PM

your furnace has what is called a LITE PORT. its just a little light that flashes or stays on or off. the IFC uses this to inform humans of the current status of the furnace by what the light does [ie 2 flashes might mean open limit or whatever] wait for the furnace to start acting up, then observe the light. your owners manual and or the blower door panel will provide you with more insight on how to read the LITE PORT code. This code tells you why the IFC will not allow the furnace to run. running the blower is something that the IFC will do on many faults as a safety precaucaution. anyways, once you read and interpret the code, turn off the furnace and leave it off and do not attempt to operate the furnace until it is repaired [preferably by a qualified serviceperson] as the IFC shut down the furnace because the furnace has done something that it is not supposed to do, something that is not safe.

captjack 01-20-2007 01:26 PM

Thanks for the input so far. I feel I might need to clarify a point though before I attempt what you suggest. Here is what happens, thermostat calls for heat, induction blower runs, igniter lites, burners turn on and nice clean blue flame emits from burners. No white or yellow color. house heats, set temp is reached,(70 degrees), burners shut off, main blower continues to run and will not stop till furnace power is cut. last night it did the same, we were not home, blower ran and temp in home was down to 63 degrees when we arrived blower still circulating unheated air since the burners had shut off. I turned furnace power off, then back on, furnace has been cycling properly since then, but at anytime it could go back to its old tricks. I have had the furnace do this as soon as a day or two, and as long as months in between malfunctions, that is what is so baffeling. Next time it happens, I will look to see if there is an error code flashing before I cut power, dumb of me not to think of that last night. In the last year or so I have replaced the induction blower and the pressure "thingy" ( sorry for the technical term there), that attaches to it.
with clear plastic lines.
I hope this additional info helps you understand my particular problem. Thanks once again for any and all help.

Furnace_dude 01-21-2007 06:30 AM

Quote:

Originally Posted by captjack (Post 30694)
Thanks for the input so far. I feel I might need to clarify a point though before I attempt what you suggest. Here is what happens, thermostat calls for heat, induction blower runs, igniter lites, burners turn on and nice clean blue flame emits from burners. No white or yellow color. house heats, set temp is reached,(70 degrees), burners shut off, main blower continues to run and will not stop till furnace power is cut. last night it did the same, we were not home, blower ran and temp in home was down to 63 degrees when we arrived blower still circulating unheated air since the burners had shut off. I turned furnace power off, then back on, furnace has been cycling properly since then, but at anytime it could go back to its old tricks. I have had the furnace do this as soon as a day or two, and as long as months in between malfunctions, that is what is so baffeling. Next time it happens, I will look to see if there is an error code flashing before I cut power, dumb of me not to think of that last night. In the last year or so I have replaced the induction blower and the pressure "thingy" ( sorry for the technical term there), that attaches to it.
with clear plastic lines.
I hope this additional info helps you understand my particular problem. Thanks once again for any and all help.


Last year you had the draft inducer and pressure switch replaced. go and look at your IFC. Grab a flashlight [a bright white light is best] and look at the IFC, thats the computer in the blower compartment. turn the power off and remove the blower door, what you are looking for is any discoloration of the board. the board should be mostly green and a khaki color that your typical pc board is colored. look closely at the places where componets are soldered into the board. if theres a little bit of brown, black or anything that is other than the typical board. if you find that, the board is fried and needs replaced. do you have electrical problems like brown outs or power surges or has lightning struck your house?

corky3875 12-15-2008 03:51 PM

I am having this exact same problem. Was there one thing that worked?

Biozen 12-14-2010 02:15 PM

Fed up.
 
I have been experiencing the exact same problem for years: the furnace heats the house to the set temp, then the flames turn off while the blower keeps running. The temp drops but the flames don't reignite until I switch the furnace off and back on. Over the years, I've had qualified techniciens look at the furnace. They've tried different things (and charged me 150$-250$ each time ) but the problem returns at varying intervals. Last week, I woke up in the middle of the night cause it was 60 degrees. I'm fed up and considering replacing the whole system with baseboard heaters.

Any suggestions ?


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