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Originally Posted by Cosmicmuffin

RGRJ10EZAJS ser GE5D307F480514597 Got a lo-o-o-ong distance service call.,trying to be smart on what to bring. Unit fires up Ind. motor..,HSI lites burners..,runs for few seconds and shuts down. Flame sensor was cleaned. Then replaced with O.M.E. sensor.,same thing. Customer does mention "flame lite" on board does not come on. Sorry guys thats all Ive got. Thanks ahead!

2 suggestions, check ground from stepdown transformer compared to print, in other words, some transformers secondary sides one lead must be grounded to the case. Secondly, check make sure the furnace itself is grounded. I learned this lesson the hard way, with the same symptoms.

Got it! But ugly.. Went back with new board and installed. Same thing inducer starts.HSI glows,burners lite,runs for 3 sec. flame goes out. Flame lite on board does not lites! Home owners looking over my shoulder whole time,more questions than a two year old! Figure its got to be wire from board to F.Sensor. make up jumper from Molex plug straight to F.S. grd screw. Nothing! Time to check main power supply in furnace cabinet. Open up, take voltage 115V. Decide to jumper neutral and ground wire "SPLASH" W.T.F.!! Now I start interogating home owner.,He had done some "clean up" work in his Main power box this summer.,he had not been using furnace yet this year cause he was out of Propane.,he never thought that could be the problem,cause A/C worked fine all summer! I made up extension cord to another elec. circuit.,thing worked fine! Home owner says smiling.,well atleast I dont need that exspensive board ! And I said you might as well keep it...,your paying for it! Consider it an "Electricians charge"! Thanks all for the help!

The flame might not carry over everytime to the sensor. Clean or widen burner slot slightly.

Originally Posted by Mr Bill

Are you talking about the HSI or flame sensor? I did not know there was voltage to the flame sensor, I thought the flame sensor just proved itself to ground by micro amps, hey we don't do a lot of heat in Houston, so I could be wrong.

On the trane units at our school they say say should be between 30/50 volts.Units at my apt are much less around 5v. They stay energized the whole time u have a call for heat

Originally Posted by JBM1000

Isolate the flame sensor out of the equation. If you have above 45 volts to, I want 96 volts (Flame Sensor Sending Wire To Meter To Ground)..

Are you talking about the HSI or flame sensor? I did not know there was voltage to the flame sensor, I thought the flame sensor just proved itself to ground by micro amps, hey we don't do a lot of heat in Houston, so I could be wrong.

Isolate the flame sensor out of the equation. If you have above 45 volts to, I want 96 volts (Flame Sensor Sending Wire To Meter To Ground). Next just grab an 8 penny nail, hooked to sending wire and hold like a surgeon with needle-nose pliers and keep in flame and see if you get Amber light. If you have seen amber even for just a second then there "WAS" a path. Now its back to basics, Ground or board line output.

Some good points Mr.Bill..This is 1995,sensor wire does run to molex plug at board,has one harness plug inline,,i checked both. I did run a jumper wire from burner/sensor ground to board ground.

Originally Posted by Cosmicmuffin

There is two L.E.D. lites on board. Green which works..,and amber (flame) that doesnt,even when burners lite for 5 seconds. Customer says amber lite use to glow. Ordering a board Monday! Has anyone ever tried to "dead" ground flame sensor wire,or hold sensor probe on known good ground! I did, neither worked.

If the flame sensor is not grounded good, the amber light will not come on "ever" also if this unit in an early model 1993-1994 you may just need to install the remote sensor kit. Your new ground will run straight to the board, to the molex plug, the directions that come with the kit are simple and to the point. My guess is since you already have the flame sensor it's been updated, but if the ground is not making a good connection at the molex plug on the board, it will not work, even with a new board, it has to make a good connection at the plug. Until you see the amber light, when its senses flame the thing will always shut down. It could be the board, but everyone I have ever worked on I just had to relocate the ground to the molex plug with the new sensor kit, and it fixed it. If everything else works on it, and it goes through the proper sequence, my bet is it's not the board, you have a ground issue.

This is what I use. http://fieldpiece.com/accessory-heads/aua2 I could be doing something wrong, but this is how I do it. I usually do not check to ground I just check the micro amps. If it is not high enough I clean it and if it still not high enough then I will by pass the factory wire if It still is not high enough I would check from flame sense on board to ground for voltage if I do not have voltage it is the board, if I do have voltage it must be the sensor. I have yet to find a faulty sensor. Now I have cracked one accidentally trying to remove it but that of course was my fault not the flame sensors.

dogboy

Looks like I will be making another trip! Checked continuity from board to flame sensor.,good. Tried all other tests mentioned,could not get my meter to read properly? Did get a low voltage once,around 27? There is two L.E.D. lites on board. Green which works..,and amber (flame) that doesnt,even when burners lite for 5 seconds. Customer says amber lite use to glow. Ordering a board Monday! Has anyone ever tried to "dead" ground flame sensor wire,or hold sensor probe on known good ground! I did, neither worked.

Originally Posted by Jesjen829

If you check it in series how would you check to ground?

I had the same question on this forum. It was explained to me to check from common to ground on the burner the voltage potiental should be very low around .3 . I experimented with this at my school on a unit with a functioning unit with a flame sensor and got a .45 reading some were around their should prove ground. If its not good on the burner work backwards

Originally Posted by DOGBOY

I check it like I do all others, in series. I disconnect the wire from the sensor then connect one lead of my meter to the sensor and the other lead to the wire, I start the furnace and monitor the microamps. They usually go up after the igniter denergizes.

dogboy

If you check it in series how would you check to ground?

I check it like I do all others, in series. I disconnect the wire from the sensor then connect one lead of my meter to the sensor and the other lead to the wire, I start the furnace and monitor the microamps. They usually go up after the igniter denergizes.

dogboy

Originally Posted by danielworkerbee

Flame sensor must be good.
Clean burners and add grounding wire up to burners.
Check the voltage on the flame sensor wire to ground, should be above 30 volts minimum and hopefully higher.
Could be poor graounding all the way to the elec. panel.
luck dan

Do you check this with sensor still connected to wire or remove it and check before it goes off. What do you use to ground the burner?

rheem/ruud hsi boards are I found bad about not sending out the proper voltage so the flame sensor is sensing nothing. check micro amps and if below .9 replace the board.

dogboy

Originally Posted by billg

I would bring a pressure switch, contact cleaner and a board if you have it (i carry these anyway) check flame sensor wire, sometimes the harness gets damp or wet and will lock it out, pressure switch and hoses and check drain trap and hoses.

Had this happen to me on a York once. I missed it, fortunately my service manager didn't.

*

I would bring a pressure switch, contact cleaner and a board if you have it (i carry these anyway) check flame sensor wire, sometimes the harness gets damp or wet and will lock it out, pressure switch and hoses and check drain trap and hoses.

Also flame must be grounded. Make sure flame is not "lifting" off the burner.

Flame sensor must be good.
Clean burners and add grounding wire up to burners.
Check the voltage on the flame sensor wire to ground, should be above 30 volts minimum and hopefully higher.
Could be poor graounding all the way to the elec. panel.
luck dan