Good then I will redo things and put tank in the garage.

You are in Minnesota. It is below freezing and you have a new system. My experience when we installed a new system was that we were told the regulator sometimes froze up and we needed to pour a gallon of hot water on it, as it was sticking.

There are numerous problems with gas. Overfilled tanks, a tank that is supposed to be full that leaked or never was filled. Ice or water in the line, dirt. As you have not stated which side of the place the regulator is located, and I do know Minnesota has had nothing but clouds and cold that would make a regulator sticky. It sometimes in cold weather takes a few months to work out the kinks.

He HAS given us the detail of location. We may not have the solution but our thinking is logical !

The regulator is outside, immediately downstream from the tank. The tank is located on the north side of the building and never gets any sunlight.

Just do the best you can to keep all components relatively warm!

I've been planning on putting a blue flame wall unit in my new shop and running off either a 100 lb or 420 lb tank but this thread has me rethinking that idea.

On the other hand, I've been running my gas oven/range in the kitchen off first a 100 lb tank which was upgraded by the gas company to a 420 lb tank (next size up) since 1989 and have had zero issues.

What is your gas pressure at the unit and have you checked your water column. Which direction is the vent facing on your regulator in ur tank it may have gotten water in and froze. Easiest way to fix and check is take it off take it inside where warm and give it a few shakes if water comes out thays your problem. Bit I would check your water column at the unit first

Well I believe it was water freezing in regulator, I have re-plumed for the tank inside building.

Now when I test W/C (manometer) test on intake before appliance is running I have a reading of 13.5"

When it's running I have 10.5" intake side. I also tested the burner side of gas valve (manifold) when running and reading is 10".

I am reviewing the instructions and there is conflicting info in them, on table 5 it says 10" WC for an altitude of 0-2000' for LP, but in a paragraph just below it it says a minimum of 10.9" W/C for LP should be maintained for proper unit operation.

I am debating weather I should adjust it or not, the heater has been running for about a hour now. there is some orange tipping on burner flames.

The info I am referring to is on page 12 of PDF






http://www.mrheater.com/downloads/dl/file/id/255/mr_heater_big_maxx_unit_heater_manual_2018.pdf

I wanted to ad a filter and a rubber hose so I could hook up a smaller tank but Menards did not have the proper fittings for this.

That is above my pay grade on the pressure.But the orange tipped flame probably is a sign that your mixture is a bit off

Did you look inside cover of unit should be a label with minimum and maximum water column but what you got sounds about right might wanna bump it up to 11 running. Filter is not really needed you have a drip t

That is what i was thinking EJ, about filter.

Did you have water in the regulator? so it was freezing the regulator. Are you working now?

I run a lot of high BTU propane firing my ceramic kilns in MN outdoors in winter and though I don't know the specific psi your heater needs I solved a lot of my freezer up problems with a low psi variable regulator(my come from repurposed turkey fryers). The amount of surface area that is in the tank(where liquid comes gas) effects freeze up of regulator. Even a 100# tall tank has limited surface area. I need to gang a number of smaller tanks to increase area and still have trouble below zero(I do not have room for a larger round tank which would solve trouble). Tipping a partially full tank increases surface area and increase in psi is immediately heard(though not recommended as a proper solution. As 160 says this may be from the quality of todays LP(we all suffer the effects of ethanol gas on our small engines) that they say is OK.