The cheapest and quickest way to get hot water is to put a pot on the gas stove, or if you are on 240V power, then use an electric jug.
"Instant" electric heaters usually disappoint.
Just a thought if you install an on demand gas water heater and plumb it into the van you can have an external shower and sink hot water at mains pressure for around $200.00 if you shop around , I think I posted an article on a suitable system, if you search the achieves there will a few in there I'm sure
__________________
Pets are welcome but children must be leashed at all times
If you travel and stop over night ? Maybe for 2 nights ? A heat exchanger off the heater coolant hoses heats water hot enough to do dishes etc.. A coil inside a stainless or alloy tank .. We made one up on our charter boat we had..
Not a good idea, they are limited in their efficiency.
We went through three RV Hot Water units fitted at the sink, all failed, either blew the circuit breaker or burned out, needed 15 amp power point as well, we bought a Birko instead, does the job, from a power point.
There are no shortcuts to hot water at the sink.
__________________
Bevan
Friendship is not a relationship with someone whom you've known for a long time, but with someone you trust, under any circumstances.