View Full Version : Concord furnace start up after power outage
canuk5838
Nov 25, 2008, 07:53 AM
Hi everyone, I have a 3 year old Concord model CG90UA. Having a problem re-lighting the pilot after a power outage. Have followed the procedure in the manual.
The Honeywell controller is flashing an error code 4 flashes. This refers to a problem with the limit or rollout switch open?
Have tried the procedure several times. Service is called but may not get here today.
Any suggestions? They said this is a common problem but would not offer a solution over the phone.
hvac1000
Nov 25, 2008, 09:17 AM
Find the limit and or rollout switch and see if it has a very small reset button in the center of the control. The back side of the blower door has a wiring diagram.
canuk5838
Nov 25, 2008, 10:10 AM
Find the limit and or rollout switch and see if it has a very small reset button in the center of the control. The back side of the blower door has a wiring diagram.
Found both devices and there is no reset button. The limit switch is a round black plastic device and the rollout switch is a fiberboard with 2 leads. Removed it and there was no reset inside.
Could this have something to do with the Honeywell controller? Can't find a number on it.
canuk5838
Nov 25, 2008, 10:38 AM
Found both devices and there is no reset button. The limit switch is a round black plastic device and the rollout switch is a fiberboard with 2 leads. Removed it and there was no reset inside.
Could this have something to do with the Honeywell controller? Can't find a number on it.
Found it SV9520.
The product manual says
4 flashes = "Limit string open.
Combustion air blower is energized. If control
system includes ST9160 Electronic Fan Timer,
the heat speed circulating air fan will be
energized until the limit string resets"
Doesn't say how long this will take.
KISS
Nov 25, 2008, 12:17 PM
It might take a couple of hours until it cools.
canuk5838
Dec 6, 2008, 12:03 PM
It's taken awhile to respond with a thank you to those that offered help on this problem.
I found the reset but it is not located at either device. It is up on the left side of the burner box. Learned two valuable lessons and would like to pass them along.
1. location of reset as stated above.
2. Root cause of the problem. When the tech arrived he showed me the reset and proceeded to restart the furnace. It would not star and the rollout switch tripped again.
He then went outside. My furnace is vented via a horizontal black pipe which goes to the side of my home. There is an elbow with a screen on it. He removed the elbow and found the pipe was plugged up with wasp nests. After using a bar with a hook on the end, he removed the nests and reinstalled the elbow.
The furnace restarted on the next try. No parts were needed but he did a complete inspection to insure everything was operating OK.
THe whole ordeal cost $140.00 but maybe I can save someone a service call if this happens to them.
My new fall maintenance plan is to make sure the filter is changed and check the exhaust vent to insure there are no obstructions.
This is a common problem in SW Ontario.
hvac1000
Dec 6, 2008, 03:38 PM
Glad you got it going,,
MarkwithaK
Dec 6, 2008, 03:53 PM
This is a commom problem in SW Ontario.
Not just SW Ontario. :(
I've been on snow covered roofs shoveling out flue pipes here in NW Indiana.