[timcoon]

Hi All,
I have been struggling with my Bryant 394GAW furnace (20+ years old) over the last couple of days. Pilot would light ok and then burners would light ok, but then they would go out after ten seconds or so. That would repeat a time or two until the blower would finally come on. After much online searching, I ended up cleaning and sanding the flame-sensing pilot assembly as well as the pilot gas tube. Seems to be working much better now, but the pilot flame itself is now MUCH bigger than it was before.

Before the cleaning it was maybe a one-inch, easy-going flame, all nice and blue like it's supposed to be. After the cleaning, it's still nice and blue, but is now at least three-inches long and a little more jet-like. Is this normal for this type of furnace? Again, the sequence of operations seems to be fine, and everything is working better than before.

I am fairly certain that I didn't inadvertantly adjust or change anything else...just the cleaning.

Thanks for any input.

Tim

 

[hvaclover]

You either dropped the pilot orifice or enlarged the orifice opening.

 

[beenthere]

You did something.

 

[timcoon]

I know that I "did something," I just don't know if I did something wrong, or simply cleaned out a dirty orifice and the flame is now the way it should be.

Is there a "right" size for the pilot flame? There is actually some discoloration on the wall of the heat exchanger, adjacent to the pilot, as if the pilot flame used to be this way.

I guess I am wondering...is it wrong? And if so, can I adjust something like that somehow? Can I "raise" the orifice if I dropped it? Or do I need to replace the pilot/ignitor assembly?

Thanks again.

 

[beenthere]

Did you put the orfice in upside down.

You can adjust the amount of gas going ot it.
But first, you have to see if you did anything to the pilot that needs corrected first.
Did you ream the orfice out.

 

[hvaclover]

If you reamed that orifice too large than adjusting the pilot press is not going to cure your problem,

Too big an orifice with too little gas is gonna make a dirty flame.

 

[timcoon]

I never even took the orifice itself out of the assembly, so I know it is not upside down. I did use a straight pin to try and clean out the orifice, although "reaming" would be a pretty strong word for what I did. I basically just stuck the pinhead in there and twisted it a little bit to clean the hole. The pin would not go throught the hole, and I didn't force it, but I used a wee bit of pressure just to clean out any scuzz. Are they THAT precise?

 

[beenthere]

Yes they are.

 

[timcoon]

Maybe I put too much into the cleaning. Would you say that if I can get a nice soft blue flame by reducing the gas a bit, that would be okay? I would rather not replace it if I don't have to, but I will if that's the only way.

Are you familiar with the ignitor/pilot assembly I am talking about? Is there a guideline for how high the pilot flame should be?

Thanks for all your help,
Tim

 

[beenthere]

The pilot flame should engulf the top 1/3 of the thermocouple only.

You need a new orfice.

If you lower the gas down, you won't get a good air mix.

 

[timcoon]

There really isn't a thermocouple with this one, just the pilot assembly and the ignitor, so i'm not quite sure how big the perfect flame is.

It doesn't really matter, it's clear there's something wrong, I am going to go ahead and replace the assembly. It isn't worth the aggravation or the worry - bloody thing's over 20 years old anyway, it deserves a new part every now and then.

Thanks for your help!

 

[timcoon]

beenthere, would you say this is a big safety issue, if it operates like this for a few days, until my new parts arrive? As I said, everything appears to be working correctly, if not better than before - the sequence is all correct, no false burner starts, etc. - there's just the large pilot flame.

Thanks

 

[beenthere]

More of a waste of gas.

Has the potential to produce some excess CO.

Dangerous if it were to go out for some unknown reason and putting in all that excess gas, which won't always vent up the chimney.

 

[kenmac]

Wonder if he has that old bryant 3 wire pilot assy ??

 

[timcoon]

kenmac,

Yup, it's the old 3-wire pilot assembly.

 

[beenthere]

G6 pilot assmbly, I think.

 

[kenmac]

Can't picture the 1 you are talking about.. This is the 1 I was thinking of

 

[beenthere]

I'm thinking of an older one yet.

Just showing my age a little I guess. oops. LOL

 

[hvaclover]

Can't picture the 1 you are talking about.. This is the 1 I was thinking of

If it's spark then that's the one.

Only other kind was a two wire assy

 

[timcoon]

That's the one. In fact, that picture is from the website where I ordered my replacement.