Yeah should work fine, I do it now and have been for a while. Not sure what valve they have on the big guy so might need an adaptor. Also you probably used a bit more than 2gal., If they filled it in a warm day the gas expands a lot. You can only get a good read on propane by weight so don't be surprised if you go through a few tanks, still less than 80 bucks. Also to get a tank. a lot of uhuals just leave the bad tanks out that people pay them to take. Ask for or take one and exchange it at HD or Lowes, save 40-60 bucks

The answer is maybe. Depending on how cold it gets where you are and how long of a run it is to the heater the small tank may not provide enough pressure. A 40lb tank might be a good compromise, still a larger size but small enough to be moderately easy to transport for filling.

Ah, good thoughts! I'm in Coastal North Carolina. Rarely gets below freezing, but we've had a lot of nights in the 30s this winter. It's on the north side and will be regularly shaded.

The tank is just outside the fireplace. Maybe 4 feet of thin metal piping for it. Would insulating the pipe be worth it?

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It looks like the valve will fit, but good thoughts. Yeah, we only turned it on once last year on low for a few hours. The only time I'd really NEED it for heat is if the power goes out in the winter. We're in SE North Carolina so that isn't likely. If it did, I usually have a back up tank or two filled anyway for the grill or another fire table that's on the back deck.

That close the 20lb tank should be fine. Depending on how large the heater is you may only run into problems when it's very cold and the tank is low.

Second this. I use a 100 lb tank for my entire off grid cabin in Alaska. It flows fine until about -30F or so.

Given that you seem to be not using it that much, you'd be better served not using it at all. Ventless fireplaces are extraordinarily dangerous and banned (for good reason) all over the world.

https://pubmed.ncbi.nlm.nih.gov/20590920/

Within an hour of turning on a ventless fireplace, whole-home levels of toxic and dangerous combustion products exceed WHO safety levels. They literally fill your home with poison.

Wow, thank you for the info! TIL

No. Not enough propane to supply the unit. Remember for safety a propane tank is never filled to capacity. Usually around 70 percent.

So a small tank like that will run out very fast. Just buy a 100 gallon tank. And refill yourself.

Okay, but how can I refill a 100 gallon myself?

They aren't hard to handle when empty... when full... you usually need a furniture Dolly.

And a truck to take it somewhere I'm assuming. I'm probably not able to put it in the minivan.

A 20# tank is about 4.6 gallons so even at 70% you'd have about 3.2 gallons. More than the 2 gallons you used.

That's a pretty thin margin though so I would suggest you find a supplier in your area with 40 or 50 # tanks. That way if you have a cold snap you won't have to run out in the middle of it to refill. Also shouldn't be too large so that you have an issue transporting it.

I have a vent free log in my fireplace too. I use a 100 lb cylinder which holds about 26 gallon of propane. Mine says in the instructions to use a 100 lb tank minimum for proper operation. I have two of them and switch when one empties and never run out of gas. Usually one will get me thru the winter in southern Indiana.

The back of my Minivan is lower than the bed of most trucks.

My buddy who has a large tank like that absolutely uses his truck, but I'd lay down the seats and toss it in my Van if I needed to.

Probably not ideal.

The place where I refill my large tank requires an open vehicle (like a truck) and for the tank to be transported upright when you leave.

Since you only burn 2 gallons or so a winter, you can probably get by on a full 100 gallon tank for a few years (assuming you don't have to burn a pilot light all the time). And when it's empty, find a friend with a truck, or rent a Uhaul or Home Depot truck for an hour and transport it yourself.

This is the best way. Most people don't realize that propane tanks are sold as pounds of propane capacity, whereas liquid propane is sold as gallons. A gallon of propane weights more than a pound.

Is there any drawback to simply having two 20lb tanks? Switching w/ out leaving the property isn't so bad. Obviously OPs situation is more complicated than my outdoor grill.

You’ll need to transport it vertically. Once home strap it to a handtruck and wheel it down a ramp. To where ever you plan to keep it. I would advise a tie dow. For the tank.

https://youtu.be/mApuvB3Ll2M

Here is a video of a elderly couple loading 100 pound tanks off a trailer.

I would guess not. Only issue I can imagine is if the 20lb tank has too low of a pressure (but again I would guess not). Can't be for sure though so I don't want to give any definite answer.

I had the same problem so I just checked on buy and sell sights until I could get a 40 gal one. Now I am looking for a second one as a back up just in case. It fits in my trunk and is easy to get refilled.

My understanding is that typical 20lb tanks and sizes that are filled and transported commercially for resale at gas stations and what not can't be filled to max.

While you or I can take the same tank and have it filled to the max level. I have a few 20s and a single 100lb tank I use for a water heater. The 20s almost always end up at 4.5 gallons and the 100 is usually around 23.6 gallons or so when I get them refilled.

I used to fill tanks, a twenty pound tank got twenty pounds of gas, which leaves space in the tank which could’ve held ~29 pounds of gas

Is that the same WHO who told me to wear a mask‽. My friend on faceplace said they were a secret corrupt government agency. /s

Use a hand truck. Problem is transporting it. As it should be vertical. Hopefully you have a trailer or pickup truck.

Wait what? The volume does not matter for pressure. For propane/butane tanks only the temperature is of importance as they liquefy on lower temperatures and the pressure decreases. Also pressure drop in tubing/piping is neglible in low flow short run conditions. Smaller tanks do run empty quicker though.

https://www.engineeringtoolbox.com/propane-butane-mix-d_1043.html

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No, likely won’t be enough pressure to run it.

There’s a difference. It will be listed as a minimum tank size in the manual for proper performance.

The larger tanks have the ability to hold temperature better. If the heater is using a large amount of propane the smaller tanks can ice up quicker than the larger tanks.

And yes the pressure drop isn't noticeable in short runs but some use 1/2" black pipe like natural gas and a grill size tank will have a hard time if you're out like 20ft.

I asked my gas company to take me off automatic delivery, and change my account to deliver on request only. I check the tank gauge every six months or so, and call them when it's down to about 20%. (Actually these days I don't have to call — there's now a link on their website to request a delivery).

I think he meant 100 lb, not gallons. 100 gallon would be ~400 lbs! 100lb tank is still heavy though.

Lol! So topical!

This again?

I asked for that. They said they don't do that anymore.

I well then maybe one tank will be fine haha

Unless you want to buy the tank, most places place a tank for free with the assumption you'll buy gas.

I was in a similar position, except not ventless and I went straight to "take your tank and GTFO" because sleazy gas company, and I didn't buy a house to keep renting crap.

I considered the same route but never bothered. Eventually I just ripped it out, and enjoyed some significant improvement in heating efficiency from trading a hole in my wall plus metal heatsink back into solid insulated wall. My family room got more comfortable and more spacious, even after (mostly) self-installing a mini-split to replace it.

Sure, I switched my cottage from 2-80 pound tanks to 2-20s when I switched out my hot water heater to electric.

You don’t they are heavy and awkward, you need a helper. Just get a 20 lb tank and you will be fine. I used to have 2-80 pound tanks and switched to 2-20 lb tanks without a problem. They power a propane stove.

I don't know if there are other propane companies in your area, but possibly another one would.

Some 100lb tanks will have a liquid overflow valve and if you lay the tank down, you're going to have propane vapor all over your vehicle. Propane tanks need to be transported upright

Source, director of sales for a large fuel/propane distributor. I basically fuckin Hank Hill at this point.

I work a regional propane/fuel/lubricant distributor. During the tail end of COVID we ran out propane tanks because you simply couldn't get them in due to manufacturer shortages

I recommended a tonne of folks to use 100lb tanks for their fireplaces/water heats/stove tops.

Protip, you can purchase an RV regulator with hookups for two tanks, allowing you to switch from an empty to a full tank by turning a lever. This allows for you to always have a backup tank in place.

A thing to note, propane have 91500 BTU per gallon. BBQ now are 40-60000btu.

How powerfull is that heater? If it is bellow the 40kbtu then it is not worse than a BBQ.

I do agree with the 40lbs tank.

Also, do not insulate the pipe or worse, the tank. They will get colder when you use propane, you want them to warm up. And yes, cold air is still warmer than the tank!

Yes you can. Same fittings. 10lb might not last long enough but you can simply just switch it out with another ten

I run a cast iron stove with a 100 lb tank I bought and I go through a fill every year or so. The fills are up to $76 now, but I can put it in my truck myself and bring it down to the hardware store for a fill.

https://www.homedepot.com/p/Flame-King-100-lbs-Empty-Propane-Cylinder-with-POL-Valve-YSN100/301699722

https://www.acehardware.com/departments/outdoor-living/grills-and-smokers/propane-cylinders-and-accessories/85546

Look up the item number for the fireplace insert. The manufacturer should tell you the minimum tank requirements. Might even be on a label on the insert itself. I would think a 10gal tank isn't big enough. I would think 100lb minimum which is about 25gals.

I have a 30,000 btu propane heater. Per the manufacturer requirements it says 100lb tank minimum. When I run out of propane I take it to a hardware store to be refilled. It isn't light when filled but you can move it yourself.

1 gallon = 4.1ish pounds

Jeeze! I don't even imbibe and wake up every morning with a headache and cotton mouth.

I'm having a similar problem. The smaller tanks have a connection that the propane trucks can't fill where I live.

So I either don't have propane for my fireplace, pay a huge fee for the tank yearly or figure out a way to take the tank to them to refill so I have done nothing.

If you use it this rarely, get an electric heater instead. You can even get one that mimics the flames, if this is more for esthetics. This way, you won't accidentally kill your family with carbon monoxide.

The only issue you will have with a 10gal tank is it may not be able to supply enough propane. As you draw from any tank the liquid propane evaporates, as this happens it cools the remaining fluid/vapor. Drawing too quickly can cool the tank to the point that it cannot supply enough pressure. Not likely to happen with a grill in the summer, but in the cold outside during the winter and the small tank size it is possible(likely?).

An average 3-4kW chimney uses only about 500L of gas per hour. That are really low volumes, even for 1/2" pipe.

Joule Thompson effects are measurable over an orifice i.e. Regulator but not really in these cyllinders. Also with these low pressures 1-2bar JT effect would be +-1 degree Celsius for pressure drop to atmosphere entering the chimney. Yes, the tank can hold more heat as more fluid is present but will still quickly cool down/warm up with the ambient temperature.

I dont think OP has any benefit with a bigger tank looking at his consumption or other circumstances.

Good to know.

I've got a tank that looks like it came off of a forklift, how hard is it to adapt to a normal fitting? Amy unseen pitfalls there?