Mr Heater 75K Propane supply line???

[fitch]

I had contractor install my Mr Heater Big Maxx 75K in my 24x40x10 pole barn and I am not sure its correct. I have 12" or 15" of insulation in my ceiling but nothing on my walls. It does not heat up very quickly and does not get as warm as I think it should according to the threads I have read. My propane supply is 3/8" copper tubing coming off the Mr Heater regulator at the 100lb cylinder. Should it be 1/2" and will that increase the amount of propane the heater?

 

[toyotadriver]

How far is it from the tank to the heater?

I think you might have to upsize to 1/2 inch pipe. 3/8 inch might work depending on the length of run. 1/2 should work within any reasonable run length.

 

[Chetter]

I second what was said above in that the 3/8" line may be too small. I ran 1/2" black pipe for mine from the regulator to the heater, my heater is the 45000 btu propane unit from Mr Heater. Keeps my 24x32 garage toasty warm.

 

[toyotadriver]

Also, what size is your regulator? Mr. Heater makes a smaller one and a larger one. The larger one is good for something like 45k btu IIRC and the larger one is good for something like 200k btu IIRC. Obviously, you should have the larger one.

 

[SteelHorseHD]

I thought that same thing when I first hooked mine up. What is the temp. at in the garage? I have noticed that once the temp gets higher the air coming out of the heater will be much warmer. I have about 25 ft of 3/8 copper line that goes from my tank to my regulator and then 1/2 black pipe for about 10 ft to the heater. My shop is 1600 sq ft which is too much for the 75k heater but it seems to do pretty good out there. Good luck!

 

[Milton Shaw]

A ceiling fan would help to get the heat off the ceiling as that is where all of it is now. If the line is too small the flames would be smaller. check the pressure with a manometer like the instructions for the heater say and that will tell you if the line is too small. Also a 100 pound tank may not evaporate enough propane to keep the heater going if the temp outside is low. May have to manifold more than one tank if that is the problem. I have a propane generator set and it required a 500 gallon tank to evaporate enough propane to keep it satisfied.(400 gallon capacity at 80% fill). On it the line from tank to first stage regulator is on a 1/4 inch copper line and its pulling about 250k Btu.

 

[toyotadriver]

I thought that same thing when I first hooked mine up. What is the temp. at in the garage? I have noticed that once the temp gets higher the air coming out of the heater will be much warmer. I have about 25 ft of 3/8 copper line that goes from my tank to my regulator and then 1/2 black pipe for about 10 ft to the heater. My shop is 1600 sq ft which is too much for the 75k heater but it seems to do pretty good out there. Good luck!

Your 3/8 copper can handle it because it's flowing at a higher pressure.

 

[fitch]

Going to install 1/2" black pipe this weekend and throw a ceiling fan up. See what that does. It will also look nicer than just a soft copper pipe the contractor put up. Thanks for the quick feedback.

 

[SteelHorseHD]

Going to install 1/2" black pipe this weekend and throw a ceiling fan up. See what that does. It will also look nicer than just a soft copper pipe the contractor put up. Thanks for the quick feedback.

Make sure you check the supply and manifold pressures as well if your contractor didn't already do that. Having those adjusted to the right pressures can make a huge difference! I beleive it was 10.4 min on the supply line and around 10 on the monifold but your manual will tell you.