Hi All,

First, thanks for the great place to ask for help. I've learned a lot about my furnace after reading many posts online, but I have not been able to solve my problem. Here goes:

1) I have a Carrier 58DH060-CC (Made in the 80's)

2) When starting from scratch, if I turn off the power, and gas, leave it for 5-10 minutes, then come back and turn on the gas, power and set the thermostats to something above room temp, the pilot lights with the spark ignitor

3) The pilot stays lit for the most part, though sometimes the spark is a nice consistent rhythm (click-click-click-click... ) and others, the pilot will start to go out, only to have the gas line kick out more gas through the pilot orifice, which then causes the spark to ignite once again.

4) Last night, after reading some posts here, I made sure that the pilot orifice was clean

5) Currently, the furnace sounds like a car trying to start... not mechanical, but the sound of the gas line trying to keep the pilot lit... it is not a consistent sound, more "chug-chug-chug-spark....chug-chug-chug-spark"

6) According to the manual, after 40-70 seconds, while the system automatically verifies that the pilot flam has lit, the gas valve is supposed to open permitting gas to flow to the main burners. Then, 60 seconds after the main burners fire, the blower should start.

So, either A) my furnace not seeing that the pilot is lit, or B) the gas valve is not opening to allow flow to the main burners. Any ideas? Thanks so much for your time and help!

I would start by making sure the pilot orifice is clear of all debris/spider webs etc. Your pilot may be working but the possibility exists that since it does go off and on at times the flame might not be large enough to make the safety lock in and allow the burner to come on.

While you are taking the pilot assembly apart to clean it I would also check the condition of the spark lighter and any flame sensor if present.

This will give you a base line from which to start further diagnosis if necessary. Most of the times I have seen cleaning the pilot orifice as a cure for this type of problem.

Thanks for the quick reply. As per #4 in my original, lengthy post (sorry), I did make sure the orafice was clear and free. I was able to get a small gauge wire through with no problem. I also made sure any carbon residue was removed from the spark lighter... no difference in performance. I'm not sure what a flame sensor would look like... my burner looks something like the one show on this page:
http://arnoldservice.com/3_wire_pilot_burner_all.jpg

Quote:

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Originally Posted by hvac1000

I would start by making sure the pilot orifice is clear of all debris/spider webs etc. Your pilot may be working but the possibility exists that since it does go off and on at times the flame might not be large enough to make the safety lock in and allow the burner to come on.

While you are taking the pilot assembly apart to clean it i would also check the condition of the spark lighter and any flame sensor if present.

This will give you a base line from which to start further diagnosis if necessary. most of the times I have seen cleaning the pilot orifice as a cure for this type of problem.

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That picture looks like a glow coil ignition not spark.
Are you using natural gas or propane?

Do you have three wires going to the pilot assembly along with the spark ignition wire(red,white,yellow) and 5 wires on the gas valve? Just trying to remember the style of unit.

hvac1000, I'm using natural gas and found the picture whe looking for "pilot burner" in Google

T-Top, the three wires going to the pilot are green, white and yellow (from Left to Right), with the white and yellow wires close together. There ae indeed 5 wires on the gas valve, a grouping of 3 and a grouping of 2.

Is the inducer motor running on the furnace?(vent draft motor)

Ooo... here are some photos of my furnace with guts exposed...
Picasa Web Albums - Jeremy

Iis the inducer motor supposed to come on when the pilot is on, then I would say that, no, it is not running. Otherwise, earlier when the pilot would say lit and the spark was consistent, I did hear a motor running, but the burner would still never start up, or would start up randomly... hmmm.

Also, I would notice every once in a while a pretty horrible screaming sound from some motor, like it had a lot of friction ad no lubrication, but this is not consistent... just loud and rare. Coud it be related? I'm sure it must have come from the inducer motor.

Small motor top left side of the furnace it plugs in to a control board just to the right of it under the pressure switch.

I realized I had the manual and was able to find it there after I replied too hastily. I' edited my answer above, but probably while you were responding. Should this be on when the pilot is on?

The inducer motor should be on and running when you call for heat it's the first thing to start. If it does not start the pilot will light and go right back off and do this over and over because the pressure switch did not close.

Also, I can feel a smal hum-like vibration in the inducer motor when calling for heat by increasing the thermostat, but the motor doesn't spin... just a hum as though it has power, but is seized up... ugh.

T-Top, thanks sooo much for sticking with me. Since the motor is NOT running, I'll take it I need to replace the motor. Anything else I could do? D I need to make sure it is getting appropriate voltage?

Thanks!

Its sounds like the motor may be shot. One thing you can try is to remove the four screws on the inducer motor housing( Not the 3 brass screws 5/16 in the triangle mount) remove the motor to make sure something is not binding the blower wheel, put a few drops of 3 in 1 oil or WD 40 on the shaft right where it goes into the motor housing and give it a good spin. Put it back together and see if it will start. You will break the gasket when you take it off but it will work fine when you put it back. Its all negative pressure no chance of CO leaking. TURN POWER OFF FIRST!! Good luck.

Yes inducer motor should run in preparation for the main burner to come on.

Those Bryant pilot assemblys contain a warp switch that many times fail to make contact and prove to be defective. If the switch is defective the inducer motor may not run.

Hey T-Top and hvac1000, I was in the process of lubing the motor as you were typing your responses, so, it appears as though I was on the right track :-) There was a sqeak that I was able to get rid of, and the motor seems to rotate freely, a little stiff, but free for the most part. I just placed it back in the furnace and still only got the hum. After almost giving up, I took the motor out, and with it still powered up (sketchy, I know) I watched the response and saw that it rotated veeeery slowly. I then took a pen and tried to give it a little extra boost, as in starting an old airplane prop and wa-la! It started rotating full speed. So, after putting it back into the furnace, I sarted up the furnace and all is god again, the house is now heating and we're all happy and excited. Woo hoo! Thanks again for all your help!

Pick yourself up a spare inducer motor for stock. You never know when it may fail again and a zero it gets real cold real fast. Glad you got it going.

hvac1000, I bow to your foresight. After working fine for about 3 hours, the inducer motor completely failed. It hums, but won't rotate on its own. It isn't seized, but just seems to not be firing up. Anyway, I had to grab some space heaters yesterday, but was able to order a new motor assembly for delivery tomorrow. Good thing I just had the fireplace fixed... makes for s good place to huddle...