Need furnace help - - LP to Natural Gas.| Off-Topic Discussion forum |

914Driver MegaDork
10/6/15 9:12 a.m.

I would like to convert a furnace from LP to natural gas and having trouble finding parts.

Olsen Ultra Max III. Model HBS-90M.

My Google-fu fails me .....

spitfirebill PowerDork
10/6/15 9:19 a.m.

I would contact the manufacturer. When I Googled the unit, it gave performance info for propane and nat gas. I'm not sure if you only have to change a regulator or the entire burner. I know precious little about this subject.

914Driver MegaDork
10/6/15 10:59 a.m.

Yeah, me too. Probably why gas scares me.

iceracer PowerDork
10/6/15 6:24 p.m.

Try your gas supplier.

rusty New Reader
10/6/15 7:52 p.m.

Not sure if this applies to you, but on our furnace it was just the jets that needed to be changed. We ordered the kit from the same supplier I got the furnace from.

914Driver MegaDork
10/6/15 8:12 p.m.

It's jets and a regulator. The guy I was helping (his house) drilled out the jets to the prescribed natural gas diameter.

Well, if your insurance guy signed off on it, you're good and I'm out.

I was never here .....

tr8todd Dork
10/6/15 8:30 p.m.

Natural gas burns at roughly 1000 BTUs per cubic foot. Propane burns at 1500 per cubic foot. That means that the orifice/jet/nozzle, whatever you want to call it needs to be roughly 2/3 the size for propane compared to nat gas. Remember its cross sectional area of a circle needs to be 2/3, not diameter. Usually the regulator just has a spring loaded orifice that needs to be flipped. Google up the model number on the unit and order the necessary conversion kit. Most units come set for natural and have to be converted to propane with a kit. I always tape the nat "kit" somewhere to the unit in case it needs to be converted back. Instructions should be available on line. Find out which supply house in your area is the vendor for that manufacturer and get the kit or ordering info through them.

foxtrapper UltimaDork
10/7/15 7:07 a.m.

While the conversion inside the furnace is simple enough, what is the story with your natural gas supply? Do you have it already run to your house? Is it plumbed and stubbed to the furnace? Otherwise, the cost of doing that (properly, with certifications and such) can get mighty pricy.