How To Clean A Blue Flame Heater

Hi All,
A little background:
I installed a blue flame (as opposed to infrared) natural gas heater in my garage. My townhouse was originally spec'd with a fire place in the living room. Well, due to the cost (and the fact that it ate up a lot of floor space), we decided not to have the fireplace installed when the unit was built. Luckily for me, the pipe fitters installed the gas line. So, I simply ran the gas line into the garage and connected it to the wall mounted heater. It's been working for about five winters now.
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The issue:
This past winter, I noticed that the pilot would sound as if a wind was blowing across it (even when the garage door was closed). It's well shielded from something like that anyway. It kind of sounded like when a microphone is exposed to the wind at an outdoor sporting event. Normally, the pilot is silent. The heater is equipped with a thermocouple so that the gas shuts off in the event the pilot goes out. So, I'm not in danger of filling my garage with natural gas and blowing me and my neighbors to bits.
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The question:
I have looked at all of the documentation that came with the heater. Nothing indicates what should be cleaned, how often to clean things or how. I normally remove the outer cover, wipe everything down and vacuum out the cob webs every autumn. Is there some way to clean the pilot orifice? I thought there may be an issue with gas pressure but the line is sized to run a fireplace and the issue has not occurred previous to last winter.
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Can someone help? I can post pictures if necessary. I can also post the Manufacturer and Model, too. The last time I checked, the manufacturer's web site was pretty poor and they are almost impossible to contact. I think they leave a lot of the customer service to their dealers. I bought this from Grainger.
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TIA – Dave.
You can blow out the burner with compressed air. Your heater should have an low oxygen sensing pilot. When they get dirty the pilot "shrinks" and eventually will not heat up the thermopile enough to keep it lit. If you blow compressed air down in the pilot that will usually fix it. Really no need to tear it all apart. If you have any trouble PM me and I can give you a call and help you straighten it out.
-John

Oh yeah if you use the canned air stuff wait awhile before you light it back up, some of that stuff is flammable. The following explosion does help clear the dust however.
The pressure may be too high for the pilot--- the sound may be the "almost about to blow itself out" sound.
If there's a valve inline, try throttling the gas line down and see if the sound stops, but the pilot stays lit.

You may need a small pressure reducer, or to repair/replace/adjust the existing one...
Thanks to the both of you. I will try both suggestions. The weather isn't quite cool enough for me to have the heater on, but it will be soon.
John, I will contact you via PM if I need more help. I have a small compressor so I won't have to use (possibly flammible) canned air.

flanga, there are actually two shut off valves, one at the unit (in the garage) and one in the basement. I will see if throttling the valve at the unit has any effect, if cleaning the pilot doesn't work.

Thanks again, Dave.
Call a professional before you blow yourself up. Natural gas isn't something you should be screwing with if you don't know what you are doing. I'm a plumbing contractor and I had a boiler flash on my a few decades ago. The flash blew the sides off of the boiler as well as blowing a wall hung lavatory off of the wall in the adjacent room.
PS
I wouldn't be throttling the main gas cock to adjust your pilot light. You would just starve the main burner. Call out a qualified technician to verified adequate line pressures and install an inline regulator if your appliance requires it. Also have them verify your installation for proper venting, proper combustion air and proper clearances. The garage with gasoline isn't a place where you want a flash to occur. It would ruin your weekend and your insurance might not cover the damage if they find out it was done without permits by an unqualified installer.

GL
+1
Every gas appliance I've worked on had a built in gas control valve/regulator. Not to be confused with the inline gas shutoff valve. If the control valve is not working right, you will need the proper pressure gage to diagnose and adjust it. A qualified tech should have that.

More likely it just needs a good cleaning. blowing it with compressed air might work. If I was doing it, I would take it apart. (Might as well do the main burner too while your in there. A lot of time they can come out as a unit, main burner and pilot.) Then I would take it out to the truck, wire brush every thing real good, blow it out real good, and vacuum it. I didn't like getting callbacks.

Walter
Do you have a drip line below where the line goes into the appliance. Nat gas has alot of moisture and condensate can build up in the line. A drip "T" should be placed in line to catch the moisture lower than where the line enters the appliance. When you are using a lower gas flow for the pilot light it could be enough to cause irregular gas flow. It will work when the appliance is on because of the increased flow. If you have a gas WHeater you will see one there.
Deacon
I'll place a bet that you've got a small chunk of sediment lodged in the pilot jet orifice and that's making the gas pass through the orifice faster than it is engineered to, causing it to mix with air more than it should and giving you the blowtorch effect. Pull the jet from the burner assembly and look at it through a magnifying glass; it should be perfectly round. Carb cleaner and compressed air will work wonders... watch yer eyes.
I sell and work on these types of heaters. 9.5 times out of ten it is fixed by blowing out the pilot. They have a small screen to filter the air before it enters the pilot to mix with the gas(this is used for the low oxygen sensing). This gets clogged with dust and causes problems.
Like the others have mentioned above don't try to adjust the pressure with the valve. It can only change the flow and cause problems.

Let us know if you get it fixed.

-John
I have contacted a professional. I cannot believe the money they want just to look (and I mean 'look', not touch, not clean, just look) at the darned thing. If I cannot complete a simple cleaning procedure to resolve the issue, I'm not going to tinker with it any further and will have a pro out to resolve the issue.
I did some more checking of the documentation and have determined that there is an in-line regulator. So, throttling the shut-off will not be something I'll do. And, I may have to have the line pressure verified. BTW, I do not store gasoline in my garage for this very reason.
It's looking like if the issue isn't dirt, I'll need to have this checked.I believe the main burner and pilot can be removed as a unit. Taking it outside will certainly help with any vision issues (kind of dark in the garage as compared to the sunlight).
Yes, I installed a drip leg. And, since the shut-off valve, in the basement, is closed, I can remove the cap and check to see if there is water in the leg. I hadn't considered that because the leg is a 6 or 8 inch nipple. But, something to check none-the-less.
I'll be sure to post what resolved the issue. What's confusing is the issue is intermittant. But, if a good cleaning doesn't do the trick then I'm sure the guys that look after my furnace will be happy to help out. Thanks everyone! Dave.
Drip legs aren't required everywhere. We have PG&E around here and the gas is fairly dry. It also has a low sulfur content and they are allowing copper for gas piping. Dirt legs aren't required in most jurisdictions around here for that reason. I don't know about you gas in Ill. Check with your gas provider and your local building department.
I noticed that the heater heater and furnace have drip legs so I installed one to be safe. I also figured that condensation might be an issue going from a constant temperature environment (underground/basement) to the garage (even though it's just a foot or so of pipe).
Well, even though the weather has been really warm here (Chicago), I decided to clean the heater and see if a little compressed air would help. I removed the cover and vacuumed the interior. I then used compressed air to clean the burner area. I knew I was in good shape when I saw a puff of rust colored dust shoot out from the pilot orifice. After reassembling everything, I lit the pilot. As usual, it lit immediately. But, I noticed that the flame burned all the way down to the pilot opening. It looked different last year. So, I let it burn for a couple of hours to see if anything changed. Nope, it burned silently for three of four hours and the flame's appearance never changed.
Thanks for all the responses and advice. I appreciate it - Dave.