The short answer
- Older uncoated brass flexible connectors are a known hazard. The Consumer Product Safety Commission says to replace them, and not to move the appliance to look.
- Every gas appliance should have its own accessible shutoff valve in the same room, ahead of the connector.
- A proper hookup uses a new listed connector every time an appliance is installed or replaced, never a reused one.
- Gas dryers need a rigid or semi-rigid metal vent to the outside. Plastic or foil vent hose is a fire risk.
- Put a carbon monoxide alarm on every level of a home with gas appliances.
The parts of a proper hookup
Behind a gas range or dryer there should be a short, simple assembly. If yours does not have every part, it is worth a look by somebody who works on gas.
- An appliance shutoff valve, a quarter-turn ball valve with a handle, on the gas pipe in the same room and within reach once the appliance is pulled out.
- A flexible appliance connector, coated stainless steel or plastic-coated, new and listed for gas, no longer than the manufacturer allows.
- Fittings made for that connector, tightened and leak-checked with a soap solution or a detector after installation.
- On appliances that require one, a sediment trap, also called a drip leg: a short capped pipe at the bottom of a tee that catches debris before it reaches the appliance controls.
Old brass connectors: the one to worry about
Decades ago many appliances were hooked up with bare, uncoated brass connectors. The ends were soldered onto the corrugated brass tube, and the solder joints can fail, especially when the connector is bent or moved. The CPSC tied failures of these connectors to deaths and injuries and recommends replacing any uncoated brass connector with a new coated one.
Here is the part that matters: the CPSC and Piedmont both say not to move the appliance to check it yourself. A weakened connector can break when the range is slid out to clean behind it. Have a professional look, and if the connector is old brass, have it replaced.
A connector you can recognize as a problem: dull gold metal with no coating, kinked or flattened, passing through a wall or floor, or connected to a pipe with no shutoff valve. Connectors are not meant to go through walls, floors or cabinets.
New appliance, new connector
Connector manufacturers treat a flexible connector as a single-use part. When you buy a new range or dryer, it should go in with a new connector sized for its BTU rating, even if the old one looks fine. Delivery crews are often not allowed to make the gas connection, which is why a gas appliance can arrive and sit unhooked.
Converting from electric to gas is a bigger job. It needs a new gas line run and sized, a shutoff valve, a permit and an inspection. For a range, also check the electrical: most gas ranges still need a standard outlet for the igniter and the clock.
Dryer venting is part of the hookup
A gas dryer burns gas to make heat, so its exhaust carries combustion products as well as lint and moisture. It must vent to the outdoors, never into a crawlspace, an attic or the room.
Use rigid or semi-rigid metal duct, as short and straight as the layout allows. White vinyl and thin foil accordion hose crush, trap lint and can burn. Clean the lint screen every load and the duct regularly, and check that the outside flap opens when the dryer runs. Weak airflow means longer run times and more lint packed where heat is.
Carbon monoxide alarms and the smell test
A gas range or dryer that is burning properly makes very little carbon monoxide. One with a blocked vent, a damaged burner or the wrong orifice can make plenty. A CO alarm on every level, and near the bedrooms, is the only way you will know. CO has no smell.
A range burner flame should be mostly blue. Lazy yellow or orange flames, soot on the pans, or a smell of gas when a burner lights are reasons to have the range checked. If you smell gas at any time, leave the house and call 911 or the gas utility from outside.
When to call a pro
Call a licensed gas contractor to hook up any new gas range or dryer, to replace an old brass or kinked connector, to add a missing shutoff valve, or to convert an appliance from electric to gas. If you smell gas, leave and call 911 or the utility first.