Can this gas fitting be saved

[Highschoolhank]

I recently purchased a new pilot assembly for my Majestic DV360 fireplace. Unfortunately the end of the pilot tube that connects to the gas valve did not have a fitting attached though it was packaged with the assembly (see pic). I presume this was a manufacturing problem. I briefly tried to push the fitting onto the end of the tube but can tell that it is a tight fit. I presume that using tools to push it on will cause damage so that it does not seal correctly. I

was thinking about putting the end of the tube in a vise held between some soft pieces of wood and then gently tapping the fitting with another piece of soft wood to see if it would go on. Any other suggestions would be appreciated.

As a alternate solution I was thinking about reusing the current pilot tube, disconnecting it from the pilot assembly but leaving it attached to the gas valve. I realize that the connection to the pilot assembly could be damaged but thought it might be worth a try.

 

[gthomas785]

That's a compression fitting you need to assemble it. The ferrule gets permanently fused to the pipe when you tighten the nut. The ferrule should be snug on the pipe. If you can't get the ferrule to go on maybe it or the pipe is slightly out of round. A bit of gentle coercion may get it to go on but don't get too stupid with it or you'll damage the tubing.

 

[coaly]

2 common ways to repair copper or aluminum tubing ends I’ve used are to clamp flaring tool die onto tubing, or carefully adjust the jaw of a adjustable wrench over the tubing and rotate. This makes the tubing perfectly round. Care should be taken with softer aluminum of course, lubricate with oil to prevent damage. This works well on tubing that has been flattened by coiling. Practice makes perfect knowing how to set the adjustable wrench jaws. You can set it using a straight, unaffected section of tubing. It will literally polish it round.

 

[Highschoolhank]

Thank you "Minister". I've examined the tubing quite thoroughly, even using a jeweler's loupe, and can see nothing amiss. I would think that the ferrule should have been pressed on the tube during manufacture. Do you think using an olive ferrule (like in this pic) instead of the one shown would allow for a proper seal?

 

[Highschoolhank]

I was able to get the original ferrule pushed onto the pilot tube so that the tube is against the ferrule "shoulder". I removed the old pilot assembly. To install the new assembly all the connecting wires and tubes need to fit through a hole about an inch in diameter. To get everything through this hole do I just need to straighten out everything, or is there a trick to getting them through the hole in the coiled-up state? Lastly, can you provide an guidance on tightening the pilot tube and thermocouple fittings into the gas valve?

 

[gthomas785]

You will most likely need to uncoil the tubing. To install the fitting you just need to hold the tubing and ferrule into the fitting and keep it "bottomed" while tightening the nut. Finger tight plus 1/4 - 1/2 of a turn should do it.

 

[Highschoolhank]

I got everything installed. No gas leak detected at the pilot tube fitting to the gas valve. Did not try to test the thermocouple fitting since there is no gas there. Unfortunately, more questions have come up.

I pushed in the PILOT knob and could hear gas coming through the pilot hood. Pushed the spark igniter several time but no ignition. Finally used a match to light pilot which occurred quickly. Pilot is much bigger than before (which was probably too small) as seen in the pics. Is it too big? The pilot assembly is admittedly a cheap one.

I checked the mV between TP and TPTH after turning PILOT knob to ON and it was over 400. Given the size of the pilot flame can the mV value get too high?

When I pushed the spark igniter I could see a spark jumping the gap between the electrode and the top of the thermocouple. So though it is probably weak I would have expected it to ignite the gas. Given that I may need a new igniter can I just get a generic one and maybe mount it to the bracket that the gas valve is mounted to (see other pic)?

I appreciate the information that everyone has supplied!

 

[gthomas785]

There should be a pilot adjustment screw somewhere on the valve I think it's the one on the upper left. If there was too much gas at the pilot that may have made it hard to light with the spark.

 

[Highschoolhank]

The pilot adjustment is actually in the lower right corner, just below the red wire--very hard to see.

I was able to turn the pilot down considerably but not sure how to judge what is right. As it is now it works except for not being able to light it with the spark igniter, with one exception. I was able to light the pilot with the spark igniter a couple times, but only after just having turned the gas off. I presume I was able to do this because of residual heat still in the pilot assembly area.

I'll try turning the pilot down more in case the spark is being smothered by the gas flow but not sure if the thermopile will still generate enough mV to make the burner work.

 

[gthomas785]

How long are you holding down the button before giving up?

 

[Highschoolhank]

If you mean the PILOT button, I'm holding it down for about 5 seconds and pushing the igniter button repeatedly during that time. I can see spark jumping from the igniter electrode to the top tip of the thermocouple most of the times I push the igniter button. But as I said before, I only got the pilot to light with the igniter 2 times. In both of those cases it was after the pilot had been on for a while so everything was still hot.

According to AI, the electrode should ground to the pilot hood so I'm going to try to reorient it. The electrode is the bent type as seen in the pic and I also now see that it is very white so probably needs cleaning.

All questions/comments are certainly appreciated!

 

[gthomas785]

Yes try to get it away from the thermopile. I'm guessing your spark is too high up. Are you on nat gas or propane? Propane is heavier than air so it will flow downward out of the pilot and may not be reaching the spark.

I would also try holding the button for a little longer than 5 seconds, as there could be some air in the pilot tube that needs to be purged out.

 

[Highschoolhank]

Natural gas. I may even try replacing the current electrode with the old one. Thanks for the quick reply!

 

[Highschoolhank]

The electrode is fixed into where it is mounted so I cannot rotate it, and since it fixed I cannot replace with the old one. I jerry-rigged up something to place the old electrode near the pilot hood and thermocouple and still no go. Often, pushing the spark igniter does not produce any spark so I'm going to try replacing it with a generic type like used for a gas grill. I think I will get a battery powered one unless you think that is not a good idea. Appreciate your input!

 

[Highschoolhank]

I ordered a manual (not battery powered) igniter.

While waiting for it, I decided to try to take the old pilot assembly apart. A few years ago I had an entry on this forum part of which related to trying to get the pilot hood off in order to try to clean the orifice. I could not get it off then, but with the entire assembly out of the fireplace I was able to remove it. The orifice seems pretty much stuck in the pilot body, it is threaded in. Hopefully I'll be able to work it out over time, but any suggestions for getting it out?

I wanted to try to see if the orifice was obstructed so I used a jewelers loupe to look into it. The actual hole appears to be rectangular, not round. I've looked many times with different light but it always looks rectangular. Does that make any sense?

 

[Highschoolhank]

I was able to get the orifice out of the old pilot body so I can get a closer look at the tiny hole and it is definitely rectangular. I've inserted a pic that is somewhat blurry but I think shows the shape. I don't see how it could have worn to that shape or how something so perfectly rectangular could have gotten stuck in there. I'll try to get some higher power magnification on it.

I had also found an ebay listing for a #51 orifice that I thought would fit the old assembly but the seller said mine takes a #65 which is not available any more. In any case, I tried inserting a 24 gauge wire which is smaller than a #65 and could not get it in.

I might reinstall the old assembly now that the old orifice appears to at least be clean. The problem with doing that is that when installing the new assembly I had a very hard time getting the thermopile fitting started into the gas valve so I cut off the end of the old thermopile to get the fitting so I could verify that I had not messed up the threads in the gas valve. I don't know if I will be able to remove the thermopile from the new assembly to transfer to the old. If I can't remove it, just for a test of the ignition and to see how the pilot looks it should be safe to hook up only the pilot tube since there is no gas from where the thermopile connects to the gas valve, correct?

 

[Millbilly]

It's supposed to be rectangular

 

[gthomas785]

You can test the pilot without hooking up the thermopile. It just won't stay lit or allow the main burner to turn on.

 

[Millbilly]

You can test the pilot without hooking up the thermopile. It just won't stay lit or allow the main burner to turn on.

It sounds like he is confusing the thermopile and thermocouple.

 

[Highschoolhank]

I certainly did confuse them. By now I know the difference but maybe "pile" is just easier to type than "couple"!

And Millbilly, can you shed any more light on the rectangular shape of the orifice? It seems like orifice sizes are always specified in terms of drill bit sizes, the bits obviously being round.