space heater works, some unburnt gas(#2) smell


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Old 12-19-01, 02:33 PM
J
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space heater works, some unburnt gas(#2) smell

Tom, thanks for the information. You mention checking an orfice and comparing its size to the btu rating but you didn't mention where this orfice was. Is it separate from the gas control valve? If it is then it may be set up for LP gas, which was the original use of this heater. There is a pipe(tube) that hooks up to the output of the control valve, and at its other end attaches to the space heater just before a round(with pie shaped openings) air shutter. Could this orfice be somewhere in the area of this attachment, and do all heaters(and other gas devices) have their own on board orfice.

With regard to the air shutter, I have played with its position, and there isn't much change from closing the pie-shaped openings(there are two) and leaving them all the way open. I've left them open all the way, assuming that would allow the maximum amount of air to mix with the gas. But, can you tell me, if there is too much air, what would be the result. Would the blue flames be smaller than optimum? Also, I notice that when I move the shutter there is a brief split second shift in the burner flames to small mostly yellow/orange flames. This happens so quickly that I assumed it was the normal occurance when the shutter was twisted...or is this a clue?

This is a great forum, I'm learning a lot.

John
 
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Old 12-19-01, 03:42 PM
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Hello John

YES! Each gas single burner appliance has it's own orifice. Heaters and other gas appliances, with multiple burners, have an orifice for every burner.

On some single burner heaters, the orifice can be located either directly on the gas valves outlet side. The orifice can be installed inside the acutal burner.....but it is rare to find any this way.

Now that you mentioned to me the heater was orginally operated on Propane...that just about answers all the prior questions. As in OH I see....hahaha

I honestly already forgot some of your prior questions and some parts of my own replies, so please excuse me here. Been answering questions and posting replies almost all day and my brain is beginning to slow down...
My type is going all to "H... in a hand basket 2!"....

Adjusting the air shutter can momentarily cause flames to act up. This is not a concern.

Opening both air shutters fully should leanout the fuel mixture causing the flames to actually lift up slightly off the burner or burners. This condition is NOT wanted.

Closing both air shutters will cause the flames to become yellow. Another condition NOT wanted. Therefore, finding the mid way point between both extremes is just about the correct setting. Slightly more opened is best for complete gas combustion.

Favor Please:
Always use the REPLY button as long as the questions pertain to the orginal posted topic. In doing so, all the questions and all the replies remain in one thread which makes it much easier to follow along for me and others reading the topic....Tanks....
 
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Old 12-23-01, 12:11 AM
J
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Tom,

I've checked the orifice size and it's a #41 drill size. Does that sound like an LP gas size. Also, the gas control instruction sheet has a table that gives Natural Gas and LP setting ranges for the gas control regulator. For Natural Gas the range is 3.0-5.0 wc, which I assume means it is adjustable through that range. There are no numbers on the control valve itself that would indicate a specific setting.

I have bought 3 drill bits, #37,#35, & #34. What would you suggest would be the best starting point, and how would I judge the results? Am I looking for a blue flame with absolutely no orange/yellow twinges, or a larger flame than before, or one that responds to the different settings of the air shutter(which presently does not produce any difference in the flame at any shutter setting).

Or should I try measuring the output pressure using the manometer connected at what seems to be the outlet pressure tap. And then using the orifice figures that you supplied in a previous message.

BTW, the reason I didn't use the REPLY button was that when I've done it that way in the past, not necessarily on this forum, I usually don't get a response...probably because the moderator is busy with current messages and doesn't check back.

You can find my original message just by looking down the list a few days.

Thanks again for the help.

John
 
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Old 12-23-01, 02:50 AM
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John

I have done something which I rarely do...{major exception}....go backwards. However, to refresh my own memory and offer you currently relevent information on this topic, I went backwards and re-read your orginal posting.

You stated that the burner is rated a 35,000 BTU's. Using the standard and commonly preset water column pressure setting of 3.5 inches of water column for 'Natural Gas' appliance regulators, the correct orifice size is a #35.

Near the bottom, in this reply, are the {Natural Gas} orifice sizes based upon the inches of water column pressure OUT of the gas appliances regulator.

Delivery pressure ranges INTO the gas valve should be between 7 to 10 inches of water column pressure....MAXIMUM. {Natural Gas}

VIP:
>>

VIP Info:
Orifice sizes listed here are per the standard Nat Gas chart.
All orifice ratings are sized slightly under the actual burners rated output, specifically not to overgas the burner.

A #35 is actually 34,500.

At 4.0 inches the correct orifice is a #36

At 4.5 inches the correct orifice is a #37

At 6.0 inches the correct orifice is a #41

At 8.0 inches the correct orifice is a #43

I do hope the information contained within this reply clearifies at the important details mentioned.

BTW:
Regarding the useage of the REPLY BUTTON.

You stated:
Quote..."You can find my original message just by looking down the list a few days."

Not to sound harsh nor brash regarding my reply here, but I do moderator 7 forums on this web site alone. What appears to be a one on one communication between you and I, isn't simply that.

Kindly consider the fact that your communicating with me one on one but I am communicating with many many others, both here on this site and elsewhere.

Therefore, please always use the REPLY button in my forums. I do not very often avoid offering a response as your implying happens within other forums.

Your consideration in this matter would be greatly appreciated.

Regards & Good Luck,
Your Forum Host & Moderator.

Fast, Fair, Friendly & Highly Efficient....but does avoid going BACKWARDS.... ......
 
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Old 12-23-01, 11:29 AM
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Tom,

about the REPLY button discussion. I guess what I didn't get is that the REPLY button must also(as well as posting the reply) send a message to you directly so that you know when there is a response. Because, on other forums I had noticed that sometimes my reply would be unanswered, and since my replies often take a week before they are produced, I assumed that the moderators just weren't able to read back that far. I've never held that against anyone and my posting of a new message for the REPLY was just my way of dealing with that perceived situation. I'm glad to know it isn't necessary.

I didn't mean to be inconsiderate, it was simply a misunder- standing on my part. I am very appreciative of the work that you and the other moderators do on these forums and they are a godsend to those of us who like to do our own repairs and need to understand how things work.

John
 
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Old 12-23-01, 12:54 PM
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No Harm....No Foul...regarding the reply button....

Hi: John

Thanks for your speedy reply back, consideration regarding the reply button and suppling updated info too.

Minor insight, for those whom may be just joining in, may also be note worthy here, regarding the useage of the reply button:

Moderators are suppose to post back replies daily, moderate their forum or forums, control the content of replies offered by others within their forms....etc...etc...etc.

However, the above isn't always possible, for a rare few on our web site, for an assortment of reasons. Overall, moderator replies posted back do follow many, if not all, of the rules for accepting the privileges of a moderator.

We, on this web site, do have and are fortunate to have an outstanding group of dedicated, experienced, knowledgeable professionals, as compared to all other FREE and FEE info sites, bar none. Even considering the "No Wages" clause here...

Several of the questions posted daily in many forums by our clients and visitors, often lack sufficient and vital problem descriptions, appliance info and other assorted details.

And there in lies yet another major cause or reason some questions get passed up. We aren't all mind readers...we are R2D2's here....WE need INPUT.....INPUT.......in order to evaluate any problem and offer professional help and advice.

YEAH! GUYS and GALS...It's a tough job but somebody has to do it.... and I do enjoy it. Fortunately for me, I do usually have the time. I am the BOSS and the wife even say's so...haha

Now it's time for you my friend to get to work fixing that 35,000 BTU fire burner...haha. ONLY 35,000 BTU's??? Why that's just a pilot lite, on some commerical equipment....hahaha

Regards,
Tom
 
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Old 12-30-01, 03:30 PM
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Hi Tom,

I'm back with some more questions about my 35,000 btu Dayton space heater, still trying to get the flame right and to get rid of the unburnt gas smell.

I noticed on the box for the new gas control valve that it was set at 3.5 w.c, so using that as a guide I first drilled out the orifice with a #37 bit. That produced a noticiable improvement: larger flame(esp noticiable with the inner blue flame), less unburnt gas smell(but still some!), more heat, but still no obvious control by changing the air shutter position. But because of the unburnt gas smell, a few days later I drilled again with the #35 bit. That produced the following, which is why I'm writing again: still some unburnt gas smell, seemingly a little less heat, inner blue flame disappeared(or blended with entire flame), and a flickering along the outer edges of the burner slits(not all slits, but the center 60%), no real control by changing the air shutter from max open to max possible closed. The burner slits have been cleaned out with a long razor knife blade, and it doesn't look like the flame is rising off the burner. But the part of the slit that turns down from the horizontal(the end of the slit towards the front) is where the flickering(or of and on of flame) is occuring.

I haven't measured the actual output gas pressure(don't have the correct adaptors yet), but I'm wondering if there are any clues here. The fact that the inner blue flame isn't visible any longer(probably blending with the outer flame) must mean something. Too much or too little orifice? Too much or too little gas pressure. Something else???

How sensitive is the size of the orifice to all this? Should I been trying #36. And if so, that means I should solder up the orifice and redrill it. Is there a particular kind of solder to use, or will any electrical type solder work?

I'm also thinking of looking for a used CO measuring device so I can check just how much unburnt gas there is, so I can correlate that with what I'm smelling. The popular CO devices that you put on the wall won't show readouts below 30 and I'm guessing that's too high for what I'm measuring. Have you ever used this kind of device?

That's all the questions I have right now. Hope you have a good New Years. Thanks again for all the help.


John Clemens
 
 

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