SL-550TR-IPI-E : Pilot is lit, sparking, no main burner

[mahjohn]

I've looked through the previous questions and am looking for some assistance/confirmation on my troubleshooting.


The pilot lights almost instantly and the spark (right electrode only) continues, but there is no main flame.

With transformer plugged in and wall switch ON, the Orange Pilot voltage is 1.17vdc while the pilot is on and sparking, however, the Green Main reads 0vdc.

I disconnected the transformer installed 2-D's, and 4-AA's (unit has a remote) and switched to ON... Nothing, no spark, nothing. Connected transformer and with the wall switch ON, pilot lights and spark continues.

If the pilot is lit and I am sparking, I think I should read 3vdc at the Green main, which should then drop to 1.5vdc in operation. As this is not happening, is the control module bad, even though it is sparking?

thanks

 

[mahjohn]

anyone....

 

[wooduser]

When the pilot is lit the spark should shut off and the main burner gas should be turned on to light off the pilot.

The ignition module needs to supply an AC voltage to the flame sensor. When the pilot burner is lit, the flame rectifies a small amount of the AC voltage into DC, which is then detected by the ignition module to verify that the pilot is lit and then tom turn on the main burner gas.

You might have a flame sensor which is covered in invisible oxides that prevent the flames from actually touching the flame sensor. Use a piece of fine sandpaper to gently clean the flame sensor of possible oxide accumulations and try it again. It doesn't take much to clean away any accumulations.

Also inspect the flame sensor wire going back to the ignition module carefully for any breaks, corrosion on the connectors or other issues that might impair having an excellent connection.

Many ignition modules use an electrical connection to chassis ground for the DC current to flow back to the ignition module to be detected, so look for a ground connection for the ignition module and be SURE that is good and free of corrosion. Removing and reinstalling any screw for that connection is a good idea.

The real way to test for defects is to measure that DC current to see if it's present and at a suitable level for the module to detect. Post the make and model of the ignition module and I'll see if I can find the specs on it for you.

 

[mahjohn]

Thanks...I had replied, then did more checking and have a better update.

The flame sensor is working great. No short to the hood and I have continuity in the wire. When the pilot is lit and sparking, Using a stick lighter, I can add a flame to the flame sensor, and the main burner will light and the sparking will stop. However, as soon as I remove the stick lighter, the main burner goes out leaving the pilot light and the sparking again.

The control module is a Dexen Industries: GM-6KA, however, it looks like this is working, as once the flame sensor gets a flame, it sends the correct voltage to the main solenoid.

I believe now the problem is the pilot flame is not strong enough. I've pulled the module and cleaned the orifice, but it has changed nothing. From what I've been reading, the flame should engulf the flame sensor which it is not, as the flame does not come up and out of the hood (see image attached).

Replace the pilot flame assembly and hope to get a higher flame out of the new one, or somehow clean the existing with a different method to get a better flame.

 

[KeithO]

Your gas control may have an adjustment for the pilot gas flow. Do you know the make and model of your gas valve ? Is this a NG application ?

Is the left electrode for spark ? It seems to be out of position relative to the pilot flame, just does not look right....

 

[mahjohn]

Your gas control may have an adjustment for the pilot gas flow. Do you know the make and model of your gas valve ? Is this a NG application ?

Is the left electrode for spark ? It seems to be out of position relative to the pilot flame, just does not look right....

Only the right one is the sparker, the left is the flame sensor and preset to that height and location. It's a safety measure to ensure sufficient gas supply and pilot flame size prior to lighting the main burner.

I believe this is the model:
https://www.fire-parts.com/collecti...arth-home-dexen-ipi-valve-750-500-natural-gas

 

[mahjohn]

Final update. Contacted fire-parts.com, they suggested replacing the pilot assembly to start with as that is the most likely culprit given the age of 11yrs. Sure enough, the $50 part fixed it instantly with 15min install using 7/16" wrench and 1/4" nut driver.

Thanks for the help, especially some other posts with detailed troubleshooting steps.

 

[Millbilly]

A little tough to diagnose through pictures, but your pilot flame looks really small. Are you on NG or LPG? For that money a new pilot Assy wouldn't hurt.

 

[mahjohn]

A little tough to diagnose through pictures, but your pilot flame looks really small. Are you on NG or LPG? For that money a new pilot Assy wouldn't hurt.

It was the new pilot assy in the picture that fixed the problem.

 

[wooduser]

With the very cold weather some people are experiencing, this problem might have been caused by having too small of a tank of propane, if indeed they do have propane. In periods of high demand, tanks may not be able to absorb enough heat to turn the liquid propane into a gas, resulting in decreased gas pressure which could cause this kind of problem.

If the problem reoccurs during the next siege of very cold weather, and you happen to have propane, this would be worth considering as a problem.