It depends.
- If it's a 4-prong outlet right now -> YES
- If it's a 3-prong outlet:
- 3-prong and you don't mind retrofitting a ground wire -> YES
- 3-prong and neutral is a bare-wire shield and one of the hot wires is white -> YES
You will need to change the breaker to an appropriate size, 120V/15-20A, and GFCI if your jurisdiction requires this. You can use a GFCI+receptacle instead of a GFCI breaker.
For 3-prong, if you can retrofit a ground wire, go 10 AWG and then you will also be able to use it in the future for modern, safe NEMA 14 dryer outlets. If you cannot retrofit a ground wire, then you'd need to reclassify each conductor, making the bare-wire neutral into "Ground"... the white hot wire into "Neutral"... and the black/color ground wire into the solitary "hot".
You must provide correct circuit protection for the washer circuit. This must be a 20A circuit, so you must change the breaker to 20A. A side-rule requires that if it's not a duplex receptacle, then the single receptacle must be 20A (with the extra "T").
In the service panel, you cap off one of the hots and then land
- the ground wire on the ground bus
- the neutral wire on the neutral bus
- the remaining-in-service hot wire on the 20A circuit breaker. Or if it's GFCI, the hot and neutral go to the breaker, and the neutral pigtail to the neutral bus.
Do not cut off excess wire, cap it and tuck it in the back of the box. That will allow you to easily retrofit back to 240V/30A if you ever get an electric dryer.
Some models of electric dryer have an electric port for a companion washer, so they are able to work together on a single 240V socket. This is done as a labor-saver in large developments (they also avoid a dryer vent by condensing, and avoid the hot water pipe by heating inside the washer.)
