You're going to have to either get a washer that accepts 240V, or change the circuit.
New Washer
Getting a new washer will depend on the manufacturer, dealer, and other factors that are off topic here.
Change the circuit
Modifying the circuit will require knowledge of electrical safety practices, and general electrical wiring principles/standards/codes. If you lack this knowledge, or are not comfortable working with electricity, please contact a local licensed Electrician.
If you decide to tackle this project yourself, here is an overview of what needs to be done. You'll be going from a configuration with two ungrounded (hot) conductors, and one grounding conductor (NEMA 6-20). To a configuration with one ungrounded (hot) conductor, one grounded (neutral) conductor, and one grounding conductor (NEMA 5-20). To do this you'll have to swap out the double pole breaker for a single pole breaker, and repurpose one of the conductors.
At the Panel
- Before you begin, you'll need to purchase a 20A single pole circuit breaker that is compatible with your service panel, and a blank panel cover insert.
- Start by turning the power off by flipping the main breaker to the
OFF
position, then verifying that power is off using a non-contact voltage tester.
- Remove the service panel cover (be careful working in the open panel, the main lugs are still energized even when the main breaker is in the
OFF
position).
- Locate the breaker for the washer.
- Remove the wires connected to the breaker (should be either black & red, or black & white).
- Remove the breaker from the panel.
- Install the new single pole breaker in one of the slots where the old double pole breaker was.
- Install the blank panel cover insert in the panel cover, so that is covers the empty space left.
- Connect the black wire that you removed from the breaker in step 5, to the new breaker.
- If the other wire from step 5 is white, connect it to the grounded (neutral) bus bar. If the wire is red, mark the wire with a bit of white tape, or a white marker, then attach it to the bus bar.
- Reinstall the panel cover.
At the receptacle
- Before you begin, you'll have to purchase a 125V 20A receptacle.
- Uninstall the old receptacle.
- Connect the black wire to the brass screw terminal on the new receptacle.
- If the other wire is white, attach it to the silver screw terminal on the new receptacle. If the other wire is red, mark it with white tape or a white marker, and attach it to the silver screw terminal on the new receptacle.
- Attach the bare or green grounding wire to the green grounding screw on the new receptacle.
- Mount the receptacle in the box, and install the cover plate.
Once everything is finished, you can flip the main breaker, and the new breaker to the ON
position.
WARNING:
This answer is only applicable in the US, and possibly Canada.
It looks like the cable was indeed originally run for a 220V stove.
When the stove was replaced with a gas stove, rather than run a new cable they just used the existing cable. This is fine as long as both ends are properly terminated.
I don't like the way they terminated the outlet though. I think they should have used a 12 AWG pigtail. ( assuming it was a NEMA 5-15 or NEMA 5-20 outlet ) Other than that I might have done the same thing depending on the difficulty of running a new cable.
( NEMA 5-15 is the designation of a US 110V 15A outlet )
If it is easy enough, I would run a 12 AWG cable from the breaker box to another box near the first with a NEMA 5-15 or 5-20 outlet.
Then either put an appropriate outlet on the existing cable with a 40A double pole breaker (assuming it is 8 AWG wire); or just put a blank cover on it.
If you do just use a blank cover, you should either ground out all of the conductors or remove the cable from the breaker box.
This way it can be left wired for both gas and electric stoves.
If it is difficult to run a new wire, I would just do what they did; except use a pigtail to connect the outlet. Don't cut back part of the wire, use an appropriately sized wire nut.
Best Answer
IF the outlet is the ONLY outlet on the circuit, it's perfectly fine to change it to a 240V outlet (or disconnect, given it's for a heat pump) and change the breaker to a two-pole 240V 15A breaker - all your 120V wiring is already rated for 250V if not 600V. Since 15A/14Ga is the minimum wire size for house wiring, the wire size is already adequate by default for a 15A circuit.
If there are other outlets on the circuit, then there's going to be a problem, or more changes / rewiring will be required.
The white wire should be remarked red (preferable, IMHO, more obviously not just tape for tape's sake) or black (or any other "hot color" so not gray, white, or green) at both ends.