My house was built in 2019 and water heater model installed (and replaced) all these instances is Bradford White 50-gallon.

The regulator freezes even when the tank is filled with 80% capacity.

liquid propane may be entering into the regulator causing it to freeze up. I've heard other issues can be related to humidity and or moisture. (you'll have to investigate why)

Does it only do this after tank has been filled? May be the level of the tank has shifted and at 80% capacity is causing liquid propane to enter regulator.

Maybe try filling only to 50% for time to see what happens to prove it or disprove it.

another issue maybe that the regulator is too small for the appliances attached to it all drawing at the same time? You identified that the water heater was replaced at some point?

If the issues go away as the tank is drawn down, I would be leaning toward filling tank to full. Maybe the fill indicator is faulty the tank has shifted some how. Fill to 50%, take notes. Fill to 60% take more notes.

If the issues still occur at 50% tank level and lower, you'll need to investigate from the perspective of moisture or some other foreign matter getting into regulator clogging it or the regulator itself is too small for the draw of the appliances attached to it.

Thick black smoke indicates incomplete combustion, typically due to lack of combustion air. This air would be CO heavy and dangerous if not fixed properly. (carbon monoxide)

I wouldn't consider this a DIY project if you continue to see thick black smoke in any capacity, as you may have more than 1 issue going on here.

There's a lot of garbage on the internet about Propane's freezing (melting) point. It's -300 degrees F (so propane never freezes at our weather temperatures or we'd all be long dead)! Don't believe anything you read from a commercial propane company web page/add (they're the ones saying it freezes at -40 degrees F - no idea why - they must all be cutting and pasting from each other's sites).

Something else is going on here, but the propane is not freezing in your regulator. It may be something to do with water vapor in the tank which would be improved with tanks that are fuller (but not necessarily eliminated). If you rent your tank, have them replace it and the regulator.

Hi, Sentha,

You have a safety issue. I recommend you contact your LP gas supplier and have them investigate the problem as soon as possible. That said, a couple of comments:

You don't need to do experiments at various tank fill levels nor to become an expert in thermodynamics. You do need to ensure that the tank and regulator(s) are the appropriate size and type for the required vaporization rate. That rate assumes all your LP-fired appliances are demanding fuel at the same time and at the particular low outdoor temperature you expect in your area. You'll also need to verify the tank and piping are installed per best practices. Your LP gas supplier should be able to do all of that.

Regulators fail. I have been on propane since the 70’s. I rebuilt a regulator in the 80’s and replaced it in the 90’s.

A neighbor had mud wasps build a next on his regulator, maybe your screen is compromised. I was fortunate, my father’s fishing buddy was a plumber, he helped me.

I recommend contacting your propane company.

I can walk a person through troubleshooting and repair IF THEY ALREADY HAVE BASIC KNOWLEDGE of plumbing AND gas but I'll be in hell before I tell a homeowner what to tell their supplier to tell their employee to do.

If you are willing to help me help you,I'll be ha.ppy to do so. Do you own the tank? Are you buying gas from a large corporate company? If the answer is yes to both find a mom and pop supplier to supply your gas. The mom and pop will fix your problem free or cost ($5 in 90% of freeze-ups) . If your builder installed it you probably own the tank which is important in Texas. If tank is owned by a supplier other suppliers or forbidden to put gas in tank or work on system. If tank is owned by big shots, ask mom and pop to remove tank,install theirs, pump gas from big shot's into new tank then call big shot to come pick his tank up. If tank isn't gone within two months send big shot letter of demand with 30 days to come get tank off your property or relinquish ownership. If they don't comply, post back here and I'll tell you how to become legal owner and sell tank (or give it to mom and pop if they treated you well.

Bottom line for op and lurkers ,Stay away from cooperate propane suppliers and keep your business local. Mom and pop would have fixed this first time it happened.