Pilot on but no igntion
#1
03-31-08, 08:02 AM
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Pilot on but no igntion
Hello all and thanks in advance for whatever advice you can offer.
I have a Rheem Furnace RGDA 10EC-EA that came with the house when I got it. It's equipped with HSI using a Honeywell S89G controller.
Here's the intermittent problem. Thermostat calls for heat and the igniter glows nice and hot. Typically, I hear the gas valve click on and the pilot bar gets lit, and the furnace fires up. But, every now and then (once a week more or less) I walk into a cold house or wake up in one.
The igniter will glow but the furnace won’t fire up. My fix is to shut the furnace breaker off, and thermostat. Let sit for 30-45 minutes and turn everything back on. I first thought maybe the pilot rail was dirty and I cleaned it. I’ve checked all the connections and they all seem fine. Any thoughts on a bad control unit or something else?
I have a Rheem Furnace RGDA 10EC-EA that came with the house when I got it. It's equipped with HSI using a Honeywell S89G controller.
Here's the intermittent problem. Thermostat calls for heat and the igniter glows nice and hot. Typically, I hear the gas valve click on and the pilot bar gets lit, and the furnace fires up. But, every now and then (once a week more or less) I walk into a cold house or wake up in one.
The igniter will glow but the furnace won’t fire up. My fix is to shut the furnace breaker off, and thermostat. Let sit for 30-45 minutes and turn everything back on. I first thought maybe the pilot rail was dirty and I cleaned it. I’ve checked all the connections and they all seem fine. Any thoughts on a bad control unit or something else?
#3
03-31-08, 07:52 PM
Heating Repair
Have you ever seen the unit fail (does it fire and then turn off or not fire at al then lock out) before you turn it off next time look for a flashing light that will geve you a helpful failure code the code legend will be on the wiring diagram.
#4
04-01-08, 05:51 PM
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Originally Posted by KField
Mkae sure the flame sensor is clean (use steel wool) and that the pilot flame strikes it squarely. If that doesn't help, I would suspect the S89.
Ken
Ken
#6
04-01-08, 05:54 PM
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Originally Posted by mike n
Have you ever seen the unit fail (does it fire and then turn off or not fire at al then lock out) before you turn it off next time look for a flashing light that will geve you a helpful failure code the code legend will be on the wiring diagram.
#7
04-01-08, 05:58 PM
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Originally Posted by KField
Look for the 'sense' terminal on the S89 and follow the wire back to the sensor.
Ken
Ken
#8
04-04-08, 05:06 PM
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Originally Posted by RochesterGordon
Thanks! I will give it a try.
Igniter still stays on, no pilot gas. Will the igniter stay lit on lockout?
Last edited by RochesterGordon; 04-04-08 at 06:49 PM.
#9
04-05-08, 04:36 AM
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No the ignitor will not stay lit after the control determines that there was flame failure. It will recycle depending on the model of the S89. It sounds liek the control is defective. Replace the ignitor also because they don't last forever and this would be a good time to change it.
Ken
Ken
#10
04-05-08, 12:03 PM
Originally Posted by RochesterGordon
The igniter will glow but the furnace won’t fire up.
When the furnace does NOT work, which is the real problem?
#11
04-15-08, 08:07 AM
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Originally Posted by KField
No the ignitor will not stay lit after the control determines that there was flame failure. It will recycle depending on the model of the S89. It sounds liek the control is defective. Replace the ignitor also because they don't last forever and this would be a good time to change it.
Ken
Ken
