Gas dryers are common in older DC houses that already have a Washington Gas line, especially rowhouses where the laundry shares a basement with the furnace and water heater. A gas dryer still needs a 4-inch vent and an ordinary 120-volt outlet like any dryer, but it also needs a properly sized gas supply, a shutoff valve within reach and a location that keeps its burner safe. Those rules come straight from the installation guide, and most of the work they describe is for a licensed gas fitter.
What two Whirlpool guides specify
Dimension guide 8562589 (RGD4100S and related models)
The Whirlpool Corporation gas dryer dimension guide lays out the gas side in one paragraph:
- •The dryer comes set up for natural gas, with LP conversion possible.
- •Rigid supply pipe should be 1/2-inch IPS.
- •Where the gas supplier and local codes allow, 3/8-inch approved tubing may be used for runs under 20 feet. Longer runs need larger tubing.
- •Pipe-joint compound must be resistant to LP gas.
- •If local codes permit, new flexible metal tubing design-certified by AGA or CSA is recommended for the final connection.
- •The dryer's gas inlet has a 3/8-inch male pipe thread.
- •An individual manual shutoff valve must be installed within 6 feet of the dryer, in accordance with the National Fuel Gas Code (ANSI Z223.1).
- •Electrically, it needs its own 120-volt circuit rated 15 or 20 amps.
Installation instructions 3405338
The Whirlpool gas dryer installation instructions add safety requirements:
- •Use a new AGA-approved gas supply line and install a shutoff valve.
- •On LP gas, a qualified person must make sure pressure doesn't exceed 13 inches of water column.
- •A 1/8-inch NPT plugged tapping, accessible for a test gauge, must be installed just upstream of the dryer's gas connection.
- •The dryer must be disconnected from the gas piping during pressure tests above 1/2 psi, and isolated by closing its shutoff valve during tests at or below 1/2 psi.
- •In a garage, the dryer's base has to be raised at least 18 inches off the floor.
- •The dryer can't share a closet or recessed area with any other fuel-burning appliance.
- •The room must stay above 45°F, or automatic cycles may not shut off.
- •Plug into a grounded 3-prong outlet. No adapter, no extension cord.
Why each rule is there
Pipe size. A burner starved of volume burns weak. Small tubing over a long distance can't deliver it, which is why the 3/8-inch allowance stops at 20 feet.
A shutoff within 6 feet. Anyone moving or servicing the dryer needs a way to stop the gas right there, without hunting for the meter.
A new connector. The guide specifies a new approved line. Reusing one that has been flexed, kinked or corroded during a previous move invites a leak.
Fuel type. Natural gas and LP use different orifices and pressures. A dryer set for one burns poorly on the other until it's converted.
The garage height rule. Fuel vapors from cars, gas cans and mowers are heavier than air and collect near the floor. Lifting the dryer 18 inches puts the burner's ignition above that layer.
One burner per closet. Two gas appliances in a small enclosed space compete for combustion air.
A homeowner's checklist (look, don't loosen)
- Check the rating plate, usually in the door well, for the gas type the dryer is set up for. DC homes on Washington Gas service use natural gas.
- Find the shutoff valve for the dryer and measure how far it is: 6 feet or less, and reachable without dragging the dryer out.
- Inspect the connector running from the valve to the dryer. You want a certified appliance connector in good shape, not kinked or crushed against the wall.
- Confirm the outlet is a grounded 3-prong receptacle with nothing plugged in between.
- Look around the dryer. In a basement or closet, note whether a water heater or furnace shares the enclosed space.
- In a detached garage, check how high the dryer's base sits off the slab.
Venting rules are the same as for electric dryers; the vent length charts apply to both.
DC-specific notes
- •Licensed work only. The DC Department of Buildings issues gas fitting permits only to licensed contractors. Its instant permit list includes replacing not more than one gas appliance on a residential project, issued to a licensed contractor. Swapping a gas dryer is not a do-it-yourself hookup in the District.
- •Basement utility rooms. Many rowhouse basements put the dryer, furnace and water heater in one space. That's fine in an open room. If a renovation boxes them into a closet, the gas dryer guide's one-burner rule applies.
- •Converting to electric. Some owners replace a gas dryer with an electric or heat pump model. That needs a 240-volt circuit and the old gas line properly capped by a licensed gas fitter.
If you smell gas
Washington Gas says to leave the building immediately, then from a safe location call 911 and the Washington Gas Emergency Leak Line at 844-WASHGAS (844-927-4427), selecting option 1. Don't smoke or light anything, don't switch lights or appliances on or off, and don't use any device that could make a spark, including phones, until you're outside.
Signs of a supply or combustion problem
- •Long drying times with a gas dryer that otherwise seems to work.
- •A burner that lights and drops out repeatedly.
- •A yellow, lazy or sooty flame visible through the burner window.
- •A gas odor near the dryer, even a faint one.
Who does what
- •Connecting, disconnecting or moving a gas dryer, or adding a shutoff valve, is licensed gas fitter work in DC.
- •LP conversion and pressure checks need a qualified technician with gauges.
- •A new or moved 120-volt outlet is for a licensed electrician.
When the hookup checks out and the dryer still tumbles without heat, the usual suspects are the igniter, gas valve coils, flame sensor or a thermal fuse. Our gas and electric dryer repair technicians diagnose those. For closet placement, read our closet installation guide.
Documents referenced
- •Whirlpool Corporation gas dryer dimension guide 8562589: pipe and tubing sizes, the 6-foot shutoff rule, natural gas default with LP option, 120-volt circuit.
- •Whirlpool gas dryer installation instructions 3405338: new approved supply line, LP pressure ceiling, gauge tapping, garage height, one burner per closet, room temperature.
- •Washington Gas: Natural gas safety: what to do if you smell gas.