Converting BigMaxx Propane to Natural Gas

[Mmfh]

Hey guys,

I may have just got lucky and got me a 75,000 "New" BigMaxx for next to nothing, but it was originally setup to use propane. I want to use NG.

Helped a friend install this one in his pole barn, he doesn't think its large enough for his place and is looking for something much bigger. I will end up with the one we just installed, and only used once. It has about 4 hrs run time.

I found online a kit that looks to be just 4 or 5 jets that you change, different size hole for the different type of gas. Some guys I read say that the Gas valve is different and maybe even need a regulator?

Anyone here have any experience with doing a conversion, and can confirm if just changing the jets will do it or if more is necessary to make it work.

Is this something I should get excited about or just let it go?? Or should I call the manufacturer and see what they say??

Thank You!

Mm

 

[dave67fd]

GAS CONVERSION KIT
Can be purchased at any Enerco / Mr. Heater dealer or direct from
the factory under the following numbers

75LP---TO--NG-----60071

http://www.mrheater.com/productdetails_extended.aspx?catid=50&id=462&prodid=

This info is in the manual.
When you purchase the kit it should come with all the required installation instructions.
Unless your an expert or close to one, make sure you have the unit properly set up and proper manifold/line pressures are set.

http://www.northerntool.com/downloads/manuals/172645.pdf

 

[Mmfh]

Thanks for those links! I've been doing some reading on this and I keep coming up with different answers, some guys say the kit is all you need, others say you need to know which gas valve you have in the unit, some say you need to adjust the pressure with a Manometer.

Before I tell him I want the heater, I need to make sure of the cost to get it going so I know what to tell my wife.

Thanks very much!

Mm

 

[dave67fd]

I'm pretty sure the kit will convert the "gas valve" with this conversion kit. They sell the individual NG/LP Robert Shaw gas valves as a repair replacement units but the kit will change out the orifices within the valve to make the conversion.

Purchasing the conversion kit ($40+) should be the least of your worries. Depending on what you do yourself and how well you adhere/follow codes consider all the costs of hanging the heater, purchasing/installing the vent and gas system and wiring for power and thermostat.

The line and manifold pressures do need to be readjusted once the kit is installed. This again should be done by your gas supplier/HVAC tech etc.. unless your comfortable with it.

 

[Mmfh]

I'll be doing the entire job myself, I'm perfectly comfortable doing all of it. I just need to learn a few things before or as I'm doing it.

Looks like I'm going to need a "Manometer" for setting the pressure. This is all pretty basic stuff, before I tell my buddy I will take it off his hands I wanted to run the job through my head to ward off any surprises.

If I tell me Wife its going to cost a $100 to do the job, it needs to be very close to that.
Money is definitively an issue, time, not so much.

Thanks again for your time,

Mm

 

[dave67fd]

There's many threads on here on the Big Maxx install so do a search to help you out.

Just remember to locate it in an area that will blow the heat "towards" your coldest area like overhead doors, windows or entryways for maximum benifit. Also keep in mind if you are doing a vertical or horizontal vent to allow a proper location for it.

Whether you need to follow codes or not you should keep the all standards into account for your own safety.

 

[SteelHorseHD]

Make sure you know what type of gas valve it has in it. They used to put the Robert Shaw valves in them but have recently switched to Honeywell valves. I ran into this issue when I ordered my conversion kit. They sent me the kit for the Robert Shaw but I needed the other one. I think I only paid about $25 for my conversion kit which came with orifices and the new spring and screw.

You might want to reseach the vent pipe and gas line a little bit. I think my vent pipe cost me around $130 all together. If I tell my wife that something will cost $100 she already knows that it will probably be more like $300. She's used to it lol. Good luck!

 

[rasit]

I'll be doing the entire job myself, I'm perfectly comfortable doing all of it. I just need to learn a few things before or as I'm doing it.
Looks like I'm going to need a "Manometer" for setting the presssure.
Mm

Since you are a DIY'er google "homemade manometer". Easy to make with clear tubing.......

 

[Mmfh]

I'm trying to figure out something here that I can't find searching around. Can I share the flue for the water heater and the BigMaxx heater? One hole going through the roof?

The Big Maxx has a power vent, the water heater exhaust doesn't fit tight up against the top of the water heater. Sits on a stand afair so oxygen goes up the pipe with the exhaust I guess.

Will the power vent on the heater have a chance of pushing the exhaust the wrong way if the water heater isn't heating? And exhaust out between the top of the water heater and the beginning of the flue going outside.

Kinda hard to explain, I'm hoping something will be familiar with what I'm talking about and know what I mean.

Thank you!

 

[SteelHorseHD]

I understand what you are talking about but I am in no position to tell you that it is okay because honestly, I don't know. I would think that there would be some back pressure on your water heater if it has an opening in it to let air in but I don't know. Are you just trying to find a way to reduce the amount of vent pipe you will need? Obviously it you be better to only have one opening in your roof as opposed to two. Good luck!

 

[Mmfh]

I understand what you are talking about but I am in no position to tell you that it is okay because honestly, I don't know. I would think that there would be some back pressure on your water heater if it has an opening in it to let air in but I don't know. Are you just trying to find a way to reduce the amount of vent pipe you will need? Obviously it you be better to only have one opening in your roof as opposed to two. Good luck!

I want to hang the heater above the water heater, its a great place for heater operation, also there is already a hole in the roof for the exhaust for the water heater.

I figure (1) hole is much better than two! Come to think of it, our old furnace for the house used to share the same flue as the water heater. It had a power vent as well.

I'll do some more research but seems so far like it will work.

Mm

 

[dave67fd]

It can be but certain restrictions apply. You should download/read the manual fully before doing anything. Once and if connected you will need to do a flue test as described in the manual.

http://www.northerntool.com/downloads/manuals/172645.pdf

The unit may be vented vertically as a single appliance or as a
common vent with other gas-fired appliances. In common
venting situations, vent connectors for other appliances must
maintain a 4" (100mm) vertical separation between the vent
connectors. Refer to common venting tables in the(American)
National Fuel Gas Code ANSI Z223.1 or (Canada) CSA B149.1
Natural Gas and Propane Installation Code for proper vent
size.