Natural Gas to Propane Conversion

yooperdave · Sep 24, 2003

How hard is it to convert a new natural gas direct vent heater to run on propane for a year or two?

Is there a kit or a orifice or something?

Thanks

Yooper Dave

kiphorn · Sep 24, 2003

I'm sure there is an orifice available. When I moved into my new home I had to have my dryer and stove converted to LP. I paid to have it done, but after watching the service man do it, I could have done it with no problem.

That being said, I left my natural gas grill at the old house because it could not be converted. /forums/images/graemlins/frown.gif

Best bet is to check with the manufacturer.

Kip

OkeeDon · Sep 24, 2003

Check with the service guy at your local LP Gas dealership. They'll usually have a box of different orifices. Essentially, the propane orifice has to have a smaller hole than the natural gas. The service guy should also have a chart that will show the conversion sizes, and a box of numbered bits that he uses to (a) measure the NG oriface to determine the BTU's; and (b) drill the new, blank orifice for the corresponding propane size.

There's also a chance that the valve has to be changed. If it's an infinite valve it should be OK, but if it has a high/medium/low setup, those are controlled by holes in the valve, and the holes for a NG valve may be too large for proper control of propane. It will still work, but the high will be too high, and the low will essentially be medium.

As has already been said, check with the manufacturer - they'll know about the valve, and will probably have a kit you can use to change it yourself.

Keep the old parts and you can convert it back if necessary.

bgott · Sep 25, 2003

RTFM /forums/images/graemlins/grin.gif...Most gas appliances have conversion instructions in the owner's manual or on a sticker in or on the unit. I don't know about your heater but most appliances will also include the necessary parts or jets to convert, look for a little Bull Durham looking sack tied onto the gas valve or gas line inside the unit.

yooperdave · Sep 25, 2003

I opened up the box and looked at the owners manual.

They show the parts which are different between the Nat gas & lp, but then they say that you should not convert between the two types of fuels.

Is this a standard note, or do you think they mean it?

I might see if I can take it back and trade it for a lp model.

Yooper Dave

OkeeDon · Sep 25, 2003

I can't think of any reason why it can't be done, especially if they show the difference in the parts. If you have a scanner and want to email me the pertinent part of the manual, I'll have a look at it and tell you what I discover. Oh, yeah, I owned a barbecue grill store and dispensed propane for over 8 years, and hold the highest propane license the state of Florida grants...

I've discovered that often the real reason why the mfr. doesn't want you to do a changeover is because messing with gas stuff is potentially dangerous - they don't want you setting your place on fire, and then have a suit come back on them because you're dead and no one knows it was you that screwed up.

bgott · Sep 26, 2003

It sounds like they are playing CYA. If you convert it using their parts I can't see what the problem would be. If the place from where you bought it has the propane unit that would be the easy way to go. If you order the conversion parts it might take half the winter to get them.

thcri · Sep 26, 2003

Some of the manufacturers out there are more and more not allowing you to convert. Water heaters is a big one, especially the power vented ones. As a company we will not convert them at all, especially with all the new law suits out there going on. If someone comes to me to convert the house we usually can do everything but the water heater. Some of the new fireplaces also can't be converted from propane to natural but can be from natural to propane. So when selling we look to the future and buy what will be in the future, convert it for now and save the parts inside the fireplace someplace.

murph

yooperdave · Sep 27, 2003

The heater is a ECO THERM model M.V. 130N by Controlled Energy Corp. out of Vermont.

The only difference between the MV130N & MV130LP are the following 3 parts:
Burner Orifice
Injector Pilot
Minimum Rate Screw

I would really like to convert because I now have a construction site with a LP tank, but next year I should be hooked into the municipal gas line.

Thanks for all the help

Yooper Dave