# IPI system, pilot lights but no gas.  No volts on green wire



## BigBreaker (Nov 3, 2015)

Hearth and Home GO24 with a Dexen GM-6KA controller.  When I turn on the system the pilot lights and burns strongly.  Sensor probe gets red hot and I've cleaned it just to be sure.  Gas valve never comes on and pilot light switches off after 60 seconds.  I have cycled it many times.  No gas.

The controller casing is warped from heat and when I do the green wire test I get zero volts before, during and after the pilot goes on.  I have read it should read 3 volts and then 1.4 or 1.5 volts.  All the wiring is connected - connections are buried in a casing for this insert and hard to manipulate.  I've read the solenoid may pull the controller line low with its low resistance so temporarily disconnect it?  Very hard to do on mine.


Is it tricky to read that green wire or does this indicate a faulty controller that I need to replace?  At this point it's either the valve, the controller or a blockage.  Strong pilot light argues against blockage I would think.
Pic of the controller:  
	

		
			
		

		
	





Little bare wire in the pic is my probe.


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## BigBreaker (Nov 3, 2015)

Update:  I checked the ohms on both the pilot and gas solenoids and they came in 40 and 60 which is about right.  The orange pilot wire reads ~0.4volts when engaged which is right...  Think my 3.0/1.5v numbers above are off.  But the gas solenoid is never triggered like the pilot.  The good read on he working pilot was pretty convincing.
Here's my source:  http://aplusair.ca/wp-content/uploads/Intellifire-troubleshooting-guide.pdf
Hmmm not seeing link but it's an intellifire troubleshooting PDF


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## DAKSY (Nov 4, 2015)

Did you try giving the solenoid a sharp "RAP" with the handle of a screwdriver?
Sometimes they get a little sticky after the off season & a little "convincing" is
needed to free them up.


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## BigBreaker (Nov 4, 2015)

DAKSY said:


> Did you try giving the solenoid a sharp "RAP" with the handle of a screwdriver?
> Sometimes they get a little sticky after the off season & a little "convincing" is
> needed to free them up.



I didn't - saw that suggestion though.  The valve itself is buried under a cover attached to the whole burner unit.  I guess I could lift up the whole thing and bang it from underneath.  I went ahead and bought a new controller.  The melted casing and some intermittent cutouts last season pointed to controller problems but the kicker is this:

My multimeter read the green wire as open-circuit / open collector the whole way through the sequence.  It was like the meter probes were utterly unconnected - not high or low, just floating.  The pilot circuit was totally different - the meter locked onto a voltage through each stage.  I know my way around electronics and the green wire just didn't seem right.  Maybe one solenoid driver (MOSFET) burned out or desoldered itself while the other one was ok.  Obviously the microcontroller inside is working or pilot sequence wouldn't happen.

The repair guy told my wife that parts and labor for a fix is the same or worse than a new unit for $900 to $1000.  So a $100 controller that fixes the issue will make me look like a hero.  Maybe it works, maybe it doesn't.  If a new controller doesn't fix the problem I'll try the "tap" and ask Amazon if they'll take it back (50/50 there I think).  In any case I'll know I didn't get suckered into a new burner without trying to fix it myself.  Monkeying around with gas lines in a valve swap is probably beyond me anyhow, so if the controller doesn't fix it and the "tap" doesn't fix it I'm not out much compared to the cost of the new unit.


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