# Propane or natural gas orifice?



## Largemouth (Feb 23, 2011)

Picked a new pilot burner for my hot water heater. It's a Honeywell replacement. Has both the LP and NG orifices. Which is which? One has a red mark on it. It gives me the dia. sizes, but I really don't want to put a micrometer on it and deform it. Too smal to tell visually for sure. Manual doesn't state which has the red marking. I need the propane one.


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## WoW (Oct 26, 2010)

One would think the one with the smaller diameter size marking would be for the propane.

I'd check with Honeywell to be sure.


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## Largemouth (Feb 23, 2011)

Actually, the propane is larger according to their literature. 0.08NG, 0.10LP. Too small of a difference to tell visually for sure. The one with the red mark does look a little larger. Tried to mic it last night, but the taper makes it impossible to get a good measurement. The unmarked orifice came preinstalled in the burner. The one with the red making was with the scews and mounting hardware. I assume the NG came installed??? Can't get a hold of Honeywell until Monday.


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## PLUMMER47 (Dec 9, 2006)

STOP!!!!!, this is why they passed laws and the price of any gas appliances went way up. What btu is your heater, the size difference should always be much larger than what you have there. Legally by law the product you purchased is supposed to be labeled NAT or LP . when you bought it did you buy a LP burner or a NAT burner. This should tell you what was originally installed. If you install the wrong one your gonna have black plumes of smoke or it will work fine. 50% chance. The orifice itself is only sometimes labeled. Natural works at .5 psi and LP runs at 10 psi. LP has twice the BTU output natural does. when at the same pressure. The cost of conversion kits and gas valves went way up due to liability for this very issue. One of the reasons a 40 gallon used to cost 125.00 and now cost 320.00 from government regulations and safety features. The red mark confuses me, LP is usually blue and nat isn't color regulated. As long as your careful you can stick anything in there to measure. Plastic bristles........ If its a power vent or newer standard heater I would not test it, as if it over fires and burns the peanut oil vial , you will then need a new heater. If its a bradford white or lochinvar, ( same heater) then you can as they are the only ones with resetable t-stats.


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## Largemouth (Feb 23, 2011)

PLUMMER47 said:


> STOP!!!!!, this is why they passed laws and the price of any gas appliances went way up. What btu is your heater, the size difference should always be much larger than what you have there. Legally by law the product you purchased is supposed to be labeled NAT or LP . when you bought it did you buy a LP burner or a NAT burner. This should tell you what was originally installed. If you install the wrong one your gonna have black plumes of smoke or it will work fine. 50% chance. The orifice itself is only sometimes labeled. Natural works at .5 psi and LP runs at 10 psi. LP has twice the BTU output natural does. when at the same pressure. The cost of conversion kits and gas valves went way up due to liability for this very issue. One of the reasons a 40 gallon used to cost 125.00 and now cost 320.00 from government regulations and safety features. The red mark confuses me, LP is usually blue and nat isn't color regulated. As long as your careful you can stick anything in there to measure. Plastic bristles........ If its a power vent or newer standard heater I would not test it, as if it over fires and burns the peanut oil vial , you will then need a new heater. If its a bradford white or lochinvar, ( same heater) then you can as they are the only ones with resetable t-stats.


 
It's the pilot burner I'm talking about, not the main burner. It's a Bradford White water heater. I took the model number to the supply store and that's what they gave me. Looks like a universal replacement because there are different brackets for different configurations. It's not labeled specifically for either type of gas. Just says it has both orifices. Supply store "thinks" the red one is LP. They were surprised it wasn't spelled out in the instructions.


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## Michihunter (Jan 8, 2003)

Bradford White's color coding is Red for LP.


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