Need to know what size to redrill the orphes from lp to natural gas model #MGR5720ADW Serial # 13051039UM

Call Rheem
Generally the company does not support changing type of gas since propane burns much hotter and has more pressure than natural gas.
You need different gas control valve, and need cast iron burner and orifice than matches that specific gas control valve.
http://waterheatertimer.org/images/IMG_1826-LP-burner-450.jpg
http://waterheatertimer.org/Water-heater-manufacturers.html

Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

You need parts from the manufacturer. The gas orifices are different sizes between natural gas and LP gas. If you try natural gas with an LP gas orifice, you will not get much flame. If you use LP gas with a natural gas orifice, you will burn off your eyebrows and possibly other things.

Hi,
The line size depends on three things...the BTU of the burner and the length of the line...and the types of gas..Natural or LP
To find the line size you nees a chart that gives you the sizing based on these factors...

Here is a chart for Natural gas and I'm sure LP is also in thei site if you need that...

http://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_826.html

heatman101

Dont know if you can get orvices for that heater but almost all gas appliances can be converted for nat to lp and lp to nat,they made a spud kit which is a blank orvice that you drill out your nat gas orvice to I think a 20 drill side and install the spud in and redrill to size usally a nat-gas orvice is around 8 to 10 sizes larger then a lp.The big thing is the gas valve and if it has a built in regulator or not,some valves can be conferted to open up the regulator pressure by the spring or a block off kit and others are fixed and cant be changed,have to replace valve.most nat-gas are at 3" to7" and lp is at 10".Hope this helps you

Hello,
You will need to replace the nat gas orifices with propane ones, as propane orifices have smaller holes than nat gas ones. If you can't find a conversion kit for your grill, take it to a local propane co and have them convert it for you. What I do is drill out the existing orifices on the grill and install a spud, then redrill the spud with the smaller hole for LP-Gas. Then you will need to buy a regulator and hose and a 20# propane cylinder, if you don't have one. You can get those things from the propane co too. Call around first and see if anyone can help you.

NOTE: If your grill data plate isn't marked with the BTU rating of each burner, look at the nat gas orifices and see if there is a number stamped on it. I can reference this number to tell you what BTU rating they are drilled for and use that to redrill for propane. If they are not stamped with a number, then I would use my nat gas orifice drills to gauge what hole size it is. Hopefully you can find a local propane co that carries these orifice drill kits and orifice spuds to get the job done. You didn't mention the grill brand or model #, so I can't help with specifics until I know what you have. I may be able to find a conversion kit online if I knew that info.
Douglas

That doesnt work with these units they are manufactured gas specific. The manifold plate would need to be changed as well as notification to Noritz to have a new serial # issued. PC board reprogram required, etc. Buy a natural gas or LP model.

WW Granger is the biggest supplier I know of for dayton. Consult them for information and if its still available. 
In lue of this find the oldest repair man you trust and ask him if he knowes anything about them. I know I could help if I could see what you have and had some more questions answered. Pilot ignition? Gas valve model? Does it have a regulator in the gas valve? Then you have to find a kit to block open the regulator. Then change the orfices to correct size or solder and redrill the old ones. Then maybe adjust the combustion air, and you may have to change the pilot burner orfice and adjust it. 
After that you can fill the LP tank.
Hope this helps IF so please grade me accordingly and Good Luck.

lp is a smaller hole so no drilling,you can get a convertion kit.

http://www.repairclinic.com/SmartSearch/SSPartDetail.aspx?PartID=1048620&PPStack=1
try this link.
do not drill out the jets they will not work properly.
I would check all your documentation you may have the convention kit with your owners manual or it may be attached to the oven.

In most cases the pressure regulator has to be changed or adjusted. The orfices on each burner, oven, broiler and surface burner may need to be changed also. Sometimes they can be adjusted. Sometimes the threads on the pipe are different also. This is to prevent accidental connection to the wrong fuel. The big difference is the gas pressure. LP is usually around 10 - 12 lbs and natural gas is usually around 3 lbs. Properly adjusted you will like natural gas much better than LP as it is slightly hotter. The information will be in the instruction book and also on the Jenn air web site. Whirlpool owns both Maytag and Jenn aire so check all sites. The conversion kit is usually less than $50.