tappan /nordyne furnace #g6rc080c-16

[torchkeeper]

gets call for heat fan start on low,ignitor glows flame start goes off in 1-2 seconds. goes through cycle a few times and stops. red light on control board reports 4 flashes. cover door saysignition failure check ground. unit is hanging from floor joists in crawlspace. on uni strut . can or should i ground unit to cold water pipeto test ground?

[dkpd1581]

The ground fault should have nothing to do with the physical case of the machine being grounded to a physical surface.  Depending on the ignitor they used on that particular model, the wiring as it enters the ceramic of the device may be loose.

Unplug and replug all the connections (with the power off of course).  The big suspects are the plastic plug connectors between the wiring and the ignitor terminals.  Push the wires deeply into the plastic halves and then push the male/ female portions of the plug components together tightly.  Do the same all along the wire path all the way back to and including the board.

An Ohm Meter and continuity check should help you zero in on the circuit break if the above suggestions dont work out

1*

[torchkeeper]

did a continuity check on gas valve where brown and yellow wires connect. open no reading!!!! need a new valve?

[torchkeeper]

also, have 24 volts at the yellow and brown wires  after igniter glows for 30 -60 seconds, so must be bad valve huh??

[dkpd1581]

To prove that the valve is bad and it is not some other safety switch and an incorrect measurement with the meter, you can send 24VAC right to the valve and listen for the click of the valve opening and closing.  No click using the jumper, no good valve.  Then its a simple replacement job then.

Good luck.

[torchkeeper]

Here we are 1 year to the day and the furnace is doing the same thing. So am I to understand the sensor gets its ground through the flame to prove a flame has been initiated ? I set themostat to call for heat , fan starts"inducer" . Ignitor glows ,valve opens, flame lights 2-3- seconds flame goes out. Goes through sequence 4-5 times ,locks out. Or it will start and run through heating cycle. If it locks out ,I reset thermostat and it will usually catch on second series of calls for heat.  Is the flame grounding feature the cause? Cleaned sensor and no change, replaced sensor and no change. How do I check to see if sensor is "seeing" flame?

Thanks,Glen

[dkpd1581]

Go to this link and check out the troubleshooting flow chart on page 21

http://www.transtaracsupply.com/pdf/g6rc_service.pdf

Is your unit in fact a 90%+ HE furnace.  If so there is a host of things to look at that can cause your problem.  I assumed it was a standard 80%.  Give the IOM  a try and let us know what you see or come up with.

Check out page 27 bottom right of page where the board's yellow light indicates a strong or weak flame sensor signal for you.  The gamete of problems range from bad flame sensor, improper pitch of PVC flue line, air proving switch.  90%+ HE units are more involved and require a broader range of things to look at.

[applianceman18007260692]

Well if you live near salt water like me you have a lot of corrosion problems what with the humidity and the salt in the air. So you need to clean and tighten all the connections,Especially burner ground, make sure the cobwebs are out of the pressure switch hose and sand down the flame sensor, the humidity dust and salt contaminates the dang sensor. The brain has to have confirmation of ignition.  It does this by measuing constantly the resistance of that sensor. If it has the slightest amount of crap on it there will be no noticable change in the resistance. The brain will think raw gas is coming out the gas valve. It will shut down. The same guys who designed this were early pioneers of space shuttle computer comunications. Go figure.

[torchkeeper]

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[torchkeeper]

Yes it is a true 90+ HE. No this unit is not near saltwater/ it is on the shore of Lake Ontario/ freshwater though . It may be corrosion and or webs as it is in a crawlspace under house. IOM stands for what?

[dkpd1581]

Installation Operations Manual

[torchkeeper]

thank you !!!!:headbang: