Four of the fuels used by appliances sold on this site are stored by the owner between uses, and each one fails differently when stored badly. Propane leaks. Charcoal absorbs moisture and, once burned, holds live embers for far longer than people expect. Wood pellets swell and jam machinery. Carbon dioxide cylinders are pressure vessels that spend most of their life sitting in a kitchen cupboard. None of this is exotic, but the handling rules are specific enough that guessing is a poor strategy.
Everything below is general guidance. The manufacturer’s manual and your local fire and building codes take precedence over any article, and codes on cylinder storage in particular differ significantly between jurisdictions.
Propane cylinders
The governing rule is simple: propane cylinders belong outdoors. That includes cylinders that are empty, because an empty cylinder still contains vapor. Storing one in a basement, a cupboard, a hallway or an attached garage puts a heavier than air flammable gas in a space where any leak will pool at floor level rather than dispersing. This applies to the cylinder for a portable unit such as the Cuisinart Grillster, whose burner the listing describes as 8,000 BTU, exactly as much as it applies to a full size tank.
Store cylinders upright and secured so they cannot fall, in a shaded and ventilated spot, away from anything that could ignite vapor. Heat matters because cylinder pressure rises with temperature, which is why the relief valve exists and why a cylinder left in a hot car or against a sun facing wall is a bad idea.
Before each use, connect the regulator and check the joint with soapy water. Bubbles mean a leak, and the response is to close the valve and stop, not to tighten harder and try again. Hoses and regulators perish, so inspect them for cracking at the bends. When transporting a cylinder, keep it upright and secured, keep the valve closed, and do not leave it in a closed vehicle.
Combination units complicate this because they hold both fuels. The Oklahoma Joe’s Canyon Combo lists propane gas and charcoal as its fuel types, which means both sets of rules apply to the same piece of equipment, and the gas side needs the same leak check even in weeks when only the charcoal side gets used.
Charcoal and ash
Charcoal itself is undemanding to store as long as it stays dry. Damp charcoal is difficult to light, burns unevenly and produces more smoke. A sealed container in a dry place solves it. Lump charcoal and briquettes behave differently in the fire but store the same way.
Two hazards are worth being blunt about. The first is carbon monoxide. Charcoal must only be burned outdoors, in open air, never in a garage, tent, enclosed porch or any indoor space, and never as a heat source. Carbon monoxide from burning charcoal has caused fatalities, it has no smell, and a kettle grill or a ceramic kamado such as the London Sunshine ceramic charcoal grill is not an exception because it has a lid.
The second is ash. Ash from a completed cook can contain live embers for many hours and sometimes days, insulated by the ash around them. Ash goes into a metal container with a lid, placed on a non combustible surface away from the building, and stays there until it is unambiguously cold. It does not go into a plastic bin or a paper bag. Equipment that makes this easy helps: the Weber Performer lists a removable high capacity aluminum ash catcher, and the Char-Broil bullet smoker lists an ash pan, both of which make the transfer a controlled operation rather than a scrape.
Lighting methods matter for storage too
If you use lighter fluid, it is a flammable liquid and gets stored as one, away from heat and out of reach of children, and it is never added to a fire that is already lit. A chimney starter avoids the issue entirely and stores as an inert piece of metal. Whichever you choose, the starter and the fuel should not live inside the grill body between uses, where moisture collects.
Wood pellets
Pellets are compressed sawdust held together by the wood’s own lignin, and they have one dominant enemy: humidity. A pellet that has absorbed moisture swells, loses integrity and turns to sawdust. Sawdust in an auger is what jams the fuel feed on every pellet appliance, and a jammed auger during a cook is at best a ruined dinner.
Store pellets in a sealed container, off a concrete floor, in a space that does not swing between hot and cold enough to cause condensation inside the container. Garage floors and outdoor sheds are the two places people most often get this wrong. Only heating pellets sold for cooking should go in a cooking appliance, since fuel pellets for heating stoves may contain binders and material that has no place in food smoke.
Just as important is emptying the hopper. Pellets left in a hopper between cooks sit in an unsealed container exposed to whatever the weather does. The Pit Boss tabletop pellet grill lists a 7 pound hopper capacity, and the larger Recteq RT-B380 holds considerably more, but the principle is the same at either size: run the hopper down or empty it if the appliance is going to sit unused, especially over a wet season.
Grease is the other stored hazard on pellet equipment, and it is the one that starts fires. The Pit Boss listing describes a simple access grease tray for grease management, and keeping that tray and the drip path clear is a routine job rather than an occasional one. Grease that has pooled and been repeatedly heated is fuel sitting directly under a heat source.
Carbon dioxide cylinders
The cylinders that feed sparkling water machines are pressure vessels, and they deserve more respect than their size suggests. The SodaStream Art ships with a 60 liter cylinder and its listing states compatibility only with the Quick Connect format, so fitment is not a detail you can improvise. The Drinkmate OmniFizz bundle ships with four cylinders, which means four pressure vessels stored in a domestic kitchen.
Store them upright, at room temperature, out of direct sun and away from heat sources including ovens and radiators, because internal pressure rises with temperature. Do not drop them, do not attempt to refill them yourself unless the manufacturer explicitly supports it, and never modify or puncture one. Empty cylinders go back through the exchange scheme rather than into household recycling, both because they are refillable assets and because a cylinder that still holds residual pressure should not be crushed.
Carbon dioxide is an asphyxiant in enclosed spaces, which is a real consideration for a cupboard full of cylinders in a small kitchen but not for a single cylinder in a ventilated home. Ventilation is the answer either way. If you can smell nothing and hear a hiss, that is a leaking cylinder and it belongs outside.
The common thread
Each of these fuels punishes a different kind of neglect: propane punishes poor sealing and indoor storage, charcoal punishes damp and careless ash disposal, pellets punish humidity, carbon dioxide punishes heat and rough handling. The equipment across the smoker listings and the charcoal grill listings on this site spans all four, and the storage requirement should be part of the buying decision rather than a discovery afterward. If you have no safe outdoor space for a cylinder, that fact rules out an entire category before any other specification matters.
