Pilot light

[mickyj]

I had a friend tell me that she smelled gas one evening and called the gas company.It was also cold in the house.
They told her her pilot light was dirty and needed to be cleaned.It is a Goodman gas fired updraft unit and has a standard type pilot.
Has anyone heard of a "dirty pilot"? I have never had a call for that before nor have I ever had a pilot problem outside of a bad ignitor or gas valve.

[oil lp man]

Maybe yours is a direct ignition with no pilot.

[Toolpusher]

Have you ever worked on a standing pilot furnace before ?

I can't say that I have ever heard of a pilot light that is still burning that had a smell of gas due to a dirty pilot.
A dirty pilot will only be more yellow in color, weak, and easy to blow out. But once it blows out it will stop the gas in about 30 seconds.
Inless it's on a gravity type furnce, where the pilot valve is different from the main gas cock.

[mike3]

Nerver seen a dirty pilot?? Yes you can get odor from a dirty pilot. When a pilot has dust introduced through the primary air open it will build up and at times there will be just enough flame striking the tcouple to keep safety open. At the same time a portion of the gas is forced out of the primary air opening because of the lint blockage. I would be unable to quess at the number of standing pilots I cleaned in my career. (thousands) You may remember seeing a pilot burning at the primary air opening. Before it flashed and started burning, gas was indeed coming out.

[Edited by mike3 on 01-30-2005 at 10:02 PM]

[blk]

Dirty pilots are one of the major reasons for pilot outages on standing pilot systems. When the orifice gets plugged/partially plugged the pilot will get "lazy" thus not striking the thermocouple effectively causing the pilotstat coil to drop out. The proper way to clean a pilot is to remove it from the pilot burner and use a proper sized reamer(broach) to clean it out...This procedure should be left up to a qualified tech, not a DIY'ers project.And yes a gas odor can be associated with a dirty pilot but when responding to any gas odor the entire system should be checked.

[Steve Wiggins]

First of all the pilot orfice isn't usually the problem. The oxygen intake slot is. Second, never "ream" out the orfice with anything. Use compressed ....uhhhhh stuff.

[mike3]

Years ago we used to have "stick drills" of various sizes that were designed to "clean" not oversize an orifice. They were the best tool. Haven't seen them in probably 25 years. Not to appear argumenative, but we find lots of orifices that need to be cleared. And you are so correct Steve. Don't ream. An oversize orifice is difficult to correct without replacing and creates problems

[Edited by mike3 on 01-30-2005 at 11:30 PM]

[blk]

I should clarify, the reamers I use don't actually enlarge the orifice opening they just remove any lint and dirt particals which have built up around and in the opening..I always select a size that is smaller than orifice opening.It should be noted as well that not all pilots are aerated pilots.I 've been to too many repeat calls where the previous tech had simply blew out the pilot.

[mike3]

amen to last sentence

[Steve Wiggins]

Reason I posted that was I had a flashback of a maintenance man telling me he knows the orfice is clean cause he "wallered it out with a scratch-all".....as we stand there and look at a concert 6" pilot flame.



[Edited by Steve Wiggins on 01-31-2005 at 07:07 AM]

[gje1]

You always said to "clean" don't "ream" mike. Yellow flame. Safety not tripped? Smells gas? Can you say Alydehids?

[ricm]

I tend to agree with Toolpusher... you have a gas valve that supplies a solid column of natural gas or L.P. through an aluminum tube (in most cases) that feeds an orifice of matching size. Once ignited, it uses ambient air to support combustion. A restriction in the orifice will net you a weak pilot flame that may or may not come in contact with the thermocouple. However, all natural gas or L.P. in the presence of the flame will be consumed. If you have natural gas or L.P. smell during a condition of a pilot light working (Weak or otherwise); One should consider checking the brass connections at both ends of the pilot line, and the possibility of 'leaking by' at the gas valve. Although it may do you little good to use your electronic combusitble gas detector right at the orifices... as residual gas may still be present as it remains 'pooled' in the space between the closed valve and the piping to the orifices.

Just some thoughts.

[ricm]

One technique I use to determine if the gas valve is leaking by is: Remove the burner assembly by the screws or fasteners that support it physically to the furnace. Of course, shutting off the gas supply... disconnect the gas line union. Re-align the burner assembly away from the burner tubes so that the orifices face upwards. Reconnect the gas union and open the gas valve shut off, and make certain the knob on the gas valve is in the 'on' position. Use leak detector soap solution on the orifices. Apply liberally so as to 'cover the orifices with soap'... watch for bubbles.

I also watch for bubbles in the bath tub too....

[mike3]

I believe the original post was directed at a dirty pilot burner. I stand by my post.