220v/240v Washer-Dryer Combo Unit?

... little help...?
:(

I believe you need 240 V running into the breaker box. I had some floor sanding done and discovered there was no 240 V running into my box. The men had to switch out with less powerful machines. Since I was having electrical work done, I asked about getting a 240V line into my apartment. The board rejected the idea because it would have disrupted all the apartments on the line and required opening the walls on a few apartments.

I'm in the UK now, and I can attest that the combo washer-dryers all suck, even the ones that work on 240v.

If you do go ahead and install one, I recommend a heated towel rack in your bathroom. All UK flats seem to have them. They've become my de facto dryer. I take the clothes out of the washer-dryer, which are damp even after four hours, and then hang them on the heated towel rack overnight.

As jelj13 says you may or may not have 208V or 240V service in your apartment panel, versus just 110V. An electrician can quickly determine this after taking off the panel cover.

240V for a washer/dryer is probably two conductors plus ground, maybe three conductors plus ground. It's not impossible some existing wiring could be reused, with outlet and breaker replaced on each end and some work in the panel, but again you need a survey (opening some existing outlets) to determine.

Right, the 120V neutral would become the second hot. At the panel end that former neutral would connect to a breaker instead of to neutral. The two 120V hot breakers are connected together so both throw at the same time. Then you replace the outlet at the other end.

I once did the reverse, changing a 240V AC circuit to 120V. The second hot became the neutral.

You shouldn't need new wiring, so maybe a few hours of an electrician's time.

Not totally clear from the original post whether this is replacing an existing washer/dryer, or if all that's existing is an outlet originally designed for something else. If the latter, you need a dedicated circuit to add this machine, and the existing outlet's circuit and/or its neutral wire may be shared among multiple outlets, impeding the use-existing concept. Again, get someone to survey, removing covers/plates to inspect wiring, and doing some circuit tracing to verify the details.

You are not going to be able to use existing 120v wiring to run a code-compliant 220V. For one, the existing wiring is probably too thin for the amperage needed on the dryer. Besides, virtually all 220v appliances need both 110v (for lights/motor/etc.) and 220v (for heat). It requires two hot legs, a neutral and a ground. You may find old setups that use three wires, but there is no ground, and not code for new installations and not doable from an exiting BX cable that has an uninsulated ground wire.