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  #1  
Old 09-04-2010, 04:18 AM
cmac2012's Avatar
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Propane outdoor radiant heaters, pilot light is a pain

I do work for a couple who are weightlifting champs and personal trainers. More money in that than I thought. Anyway they have a couple of the portable propane heaters they use when they're entertaining groups of clients in their backyard.

The pilot lights on these things are hellaciously hard to light and they use them so rarely they turn off the gas between uses so you have to relight the pilot every time. The guy is no dummie and he can't light it half the time. It gives me fits, in spite of my well known technical brilliance. You can't light the main burner w/o the pilot being lit - opens the orifice I believe.

They have an outdoor NG range - a large broiler, it's in a marble tiled kitchen counter setup in their backyard. They've had trouble with the regulator twice so he asked me if we couldn't just do away with it go straight from the gas line, which is already regulated to some extent at the meter anyway, to the burner.

If it was indoor, no way would I have done it, I don't want any dead clients and their 4 year old daughter is possibly the sweetest child in the world. But it's outdoors so I did it and it works fine. Gives them the flame height they wanted but not too high, and the regulators were giving them a tiny flame.

So we're wondering, why not try to get rid of the pilot light inside the propane heaters and just light the main burner with one of those long BBQ lighters? Probably won't be as easy as the outdoor range was to simplify but I'm willing to get into it. Might need some kind of regulator to keep the propane pressure at the right level. Then again, I think there's one on the line where it attaches to the tank.

Anybody done anything like it?

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1986 300SDL, 351K
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  #2  
Old 09-04-2010, 08:19 AM
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The heaters probably utilize a thermo-coupler. It has to be heated to release any fuel. You find them on pretty much any indoor gas appliances. I don't think removing them from the system is a good idea. Natural gas is heavier than air so it sinks. The though of a big balloon of gas (the pocket being trapped under the shield) being exposed to a flame (the lighter) sounds like a recipe for a Youtube video. Please post it.
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Old 09-04-2010, 08:56 AM
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Location: Holland, MI
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Part of the pilot light circuit is a safety for the main gas valve. If the flame detector, be it a thermocouple, infrared, etc. cannot sense a pilot flame it also cannot sense the main flame, and if it cannot sense the main flame, you run the risk of dumping gas through an orifice that does not burn. In essence, you allow a small gas leak.

Not a good idea to modify the burner, too much risk.

Better to find out why the pilot is so sensitive and hard to light, or replace the IR heaters with better units.

This opinion is worth $0.02.
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Old 09-04-2010, 09:02 AM
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Quote:
Originally Posted by Jim H View Post
Part of the pilot light circuit is a safety for the main gas valve. If the flame detector, be it a thermocouple, infrared, etc. cannot sense a pilot flame it also cannot sense the main flame, and if it cannot sense the main flame, you run the risk of dumping gas through an orifice that does not burn. In essence, you allow a small gas leak.
Agreed.

However, if the main burners are wide open without ignition, the gas leaking could probably be characterized as more than "small".

I've got a mild explosion out of a propane barbeque when the burners are open and the damn thing won't light off...........until it's good and ready.

I don't really see the risk with the infrared heater, however.........the gas cannot accumulate in any one place..........outdoors.........to present much of a risk. However, take the unit indoors and that's an entirely different discussion.
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Old 09-04-2010, 09:38 AM
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'course we could always combine this thread with this one
Labor Day Grilling Plans?
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  #6  
Old 09-04-2010, 10:23 AM
Yak Yak is offline
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Quote:
Originally Posted by Jim H View Post
Part of the pilot light circuit is a safety for the main gas valve. If the flame detector, be it a thermocouple, infrared, etc. cannot sense a pilot flame it also cannot sense the main flame, and if it cannot sense the main flame, you run the risk of dumping gas through an orifice that does not burn. In essence, you allow a small gas leak.

Not a good idea to modify the burner, too much risk.

Better to find out why the pilot is so sensitive and hard to light, or replace the IR heaters with better units.

This opinion is worth $0.02.
You're talking about two separate systems, right?

For the NG range, yes it sounds like you've defeated the safety system and the range is now getting "line" pressure with high flame instead of regulated pressure. I would speculate that maybe there's a problem with the supply or the regulator. The difficult pilot light and low flame may be two symptoms of these problems. And you've now exposed the main line to direct flame? That sounds very bad to me.

Portable propane don't use pilots, do they? You open the valve and then use the spark ignitor, like a grill. It's either battery operated or plunge operated. Change the batteries, clean the contacts...
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  #7  
Old 09-04-2010, 02:11 PM
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I sorta confused the issue with two different stories. Both are a tad dicey though the NG range doesn't worry me too much. He was adamant to give it a try. He was saying that the mock fire pit - little lava-like pieces with an NG burner beneath it - has no regulator and he has no trouble with it, and then about a year ago, he had me take the igniter off of the NG burner in the fireplace on their front porch - also outside - as it was a royal pain. That also seemed to work fine with no ill effects. He just turns it on and uses a long match. I've seen this exact sort of setup in houses and such units are sold with no pilot, no igniter so it must be legal.

But the propane heaters worry me more. Propane is heavier than air though NG is not. I have a cousin who is a copper smelting tech and has been to smelters all over the world. He tells me that some of the remote plants that have huge tanks of propane to run the operation scare the hell out of him. These complexes are not small and if a leak were to go undetected it could collect in a large enough shallow such that if it ignited you could burn your feet off before you could run out of it. Ouch.

But I don't think a small tank would be a problem and there's a small creek bed, usually dry, running through their yard (large yard), any leaked propane would just act like water and follow that out. A propane camping stove is safe enough. The regulator keeps the pressure down and you often just light them with a match.

I really like these people, their daughter is the closest I have to a God-daughter in the world. They're Polish - come from the iron curtain weightlifting school - and the guy is pretty macho, really likable, but has the sort of macho that dismisses safety concerns a bit too readily.

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