Natural Gas To Propane

pattyson

I have a used water heater that was running on natural gas and Im putting it in my rental that is on propane. What, if anything do I have to change on it? Im kindda thinking just the inlet fitting on the reg, but im not sure, bigger or smaller?
Same thing on a couple of wall furnaces.
Thanks
Dave

mdshunk

The gas valve and the pilot oriface are different on LP. Not overcome-able, but they operate at different operating pressures, (3 lb vs ll lb).

pattyson

So how do i over come this difference? Are you saying it will work on both, and nothing needs to be replaced?
or do i need a different regulator?
Dave

KillerToiletSpider

You need to replace the gas control valve to one designed for LP.

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A flush is better than a full house.

pattyson

Cool. Thanks guys.
Dave

POOLMANinCT

& all orifices in gas path... best to call a tech in. & by doing this you kiss warranty & ul compliance goodbye

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KillerToiletSpider

That would be located inside the gas control valve. As long as he gets the correct gas control valve from the Heater manufacturer it should be fine.

__________________
A flush is better than a full house.

MechanicalDVR

The gas valve and the pilot burner orifice need to be changed, you may also have to add a regulator to the gas line upsteam of the gas valve. The max pressure inside should be no more than 1/2 a pound.

MD where have you ever seen 3 lbs?????????

mdshunk

Substituten the unit "inches of water column" for "lbs" in my original statement. My mistake.

I've seen gas pressures in the "pounds" inside many times. Homes with large buried propane tanks quite often run 2 pound systems inside to keep the pipe sizes more reasonable, and have a PRV at each appliance.

MechanicalDVR

Yeah, propane is an animal of a different nature.

Dragonheart

Propane burns considerable hotter than natural gas. There is a difference in the regulated pressure between the two and the orifice for natural gas is larger.

I would suggest that you consider purchasing a water heater that was designed for Propane as it will be marked in bold print "Propane Only". Obviously altering a natural gas water heater will void all manufacturer's warranties and if something does happen you will be completely liable.

Grumpyplumber

I agree, and on top of that...changing it out is a pain, doing it yourself is a scary proposition (miss one detail and..boom).
Having a plumber/gasfitter do it wouldn't be cheap..all around it's just better to start fresh with a hew warrantied heater.

Ron The Plumber

Agreed, go with a new unit, be safe.

pattyson

After close inspection, it doesn't look like the gas control is going to come off, part of it goes into the tank to sense the temp Im sure... maybe a nut on the inside or soldered on. Ive removed and replaced gas controls on heater units, so I thought it would be easy like that, but its not.
Its used, so warrenty doesn't matter. My pops pulled it off a remodel job where he had to get a bigger one. I'll just save it for when a like kind needs replacement.
And I'll install a new one.
Dave