# LP / NG - Unusual Question...



## Peter B. (Dec 13, 2010)

Hi:

I need an answer to kind of an odd question. The question itself is actually simple and straightforward... but the reason I'm asking it is a little long. I include the explanation below if anyone's curious, but it's definitely optional. 

The question is this:

If you hook up an LP tank (20 pound) and regulator (BBQ type) to a modern <NATURAL GAS> appliance (e.g. furnace or range, with electronic ignition) will the LP gas flow as far as the orifices, as it would normally with natural gas?

Put another way, when you turn on a range burner, should you at least get a gas odor if all the lines are clear?

(By the way, the range appears to be a very standard Whirlpool of recent vintage.)

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The reason for the question... (optional).

I'm thinking of buying a trailer home. I had it inspected this week. The assumption was made that the trailer was equipped with LP appliances. An LP tank and regulator were brought to the inspection for testing purposes... and tests were attempted. Neither furnace nor range top burners fired. No gas odor was present at the range, even after the burners had been turned on for several minutes (total).

It was then 'discovered' that the appliances were set up for natural gas... and the tests were quickly stopped.

I've talked to at least one appliance repairman since, and searched for answers on the web. What I could determine was that - yes - gas should flow to the range burners and flames would likely be much higher than normal due to the increased pressure of LP... (and what might have happened if the furnace had lit is anybody's guess).

What I'm thinking is that the gas line may be obstructed... else why would nothing fire and no gas smell anywhere?

But if anyone can provide a better answer... or even a plausible hunch, it would sure help me out to know.

(By the way, I'm aware the appliances MUST be converted for use with LP. I'm just thinking there may well be a problem with gas flow... in addition.)

Thanks Very Much.

Peter B.

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## hardwareman (Oct 9, 2010)

you would definitely get gas out the orfices if a ng range or furnace were hooked up to lp, the only thing I would question is whether a bbq grill type regulator would provide enough pressure


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## nap (Dec 4, 2007)

was there or did you check for individual shut off valves at each appliance?

was there power (electrical) at the building?. This is only a guess but as a safety measure, I could see where a range with electronic ignition could have a safety valve that did not allow gas to flow when there is no power. Maybe one of the appliance guys could address that possibility.


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## hardwareman (Oct 9, 2010)

nap said:


> was there or did you check for individual shut off valves at each appliance?
> 
> was there power (electrical) at the building?. This is only a guess but as a safety measure, I could see where a range with electronic ignition could have a safety valve that did not allow gas to flow when there is no power. Maybe one of the appliance guys could address that possibility.


gas would still flow to the upper burners, the oven would need power to open the gas valve.


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## MarkusAIC (Apr 4, 2011)

Most modern furnaces have both NG and LP capability. The difference being the orifice size. You need to look up the make/model of the furnace and find the correct part number for the LP orifice. DO NOT attempt to run the unit without the correct orifice installed.
As far as the stove, it may be the same but I don't know, not being an appliance guy. Call the manufacturer and ask if that model can do LP.
The gas lines/valves could be clogged with sediment. This is a relatively easy fix for a Tech and should not be attempted by someone who doesn't know what they are doing. It is gas after all, Ka-boom


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## Peter B. (Dec 13, 2010)

hardwareman said:


> you would definitely get gas out the orfices if a ng range or furnace were hooked up to lp, the only thing I would question is whether a bbq grill type regulator would provide enough pressure





hardwareman said:


> gas would still flow to the upper burners, the oven would need power to open the gas valve.


hardwareman:

Your replies go right to my question... thanks very much.

At the moment, with the trailer 100 miles away and no final agreement yet with the seller, I have no way of solving the rest of the puzzle - 'why no gas'. But I have reported to the seller that there's an 'unknown' with respect...

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nap:

Thanks for your reply.

There did not appear to be a shut off for the furnace. If the stove has one I'd think it would almost certainly be open. The back of the stove is not easily accessible. For all intents and purposes, the trailer is new... and I assume the manufacturer would have prepped it to go right into service. But... I could be wrong.

Yes, the power was on.

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MarkusAIC:

Thanks to you as well.

No attempt will be made to use the appliances with propane before proper conversion. By and large, the LP test was 'a mistake'... performed before it was known the appliances were set up for NG.

The sediment idea is worth thinking more about.

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From other sources, two other suggestions have made some sense to me... that the gas line may take a much longer than expected time to fill... or the LP pressure regulator might cut off the gas flow if there's no 'back pressure' in the system (e.g. four open burners). The second doesn't seem all that ikely to me, but at least I can test the theory. I have a full LP tank and a brand new regulator on hand.

When all is said and done, it's probably a (dam) good thing nothing fired up, someone might easily have gotten hurt.

Again, thanks to all of you... much appreciated.

Peter B.

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## nap (Dec 4, 2007)

Peter B. said:


> --
> 
> nap:
> 
> ...


power being on would have remedied any electrical gas valve in the stove anyway.

Not knowing the situation, I thought maybe somebody might have shut everything down to avoid a possible problem, you know, something like winterizing and all.


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## Jacques (Jul 9, 2008)

Just to add to that; i would contact the manf of trailer. i'll bet there's a hidden shut off somewhere.


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## DangerMouse (Jul 17, 2008)

Look inside the furnace casing and/or on the back of the stove/oven. 
There should be a sticker(s) saying what gas it's set up for.

DM


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