Off the Grid Camping with a 110v AC Water Heater

[coyotearms]

If all you want is the hot water heater when on generator or shore power, then there is no reason to worry about this 1500W AC load. As long as that does not exceed the generator output (2000W?) or what I assume is 30 Amp (3300W) shore power capability, your'e good to go. If you never want the heater to run off the house batteries, make sure it is on a circuit that only gets power from the generator or shore, and stop reading here, except that I thought the Insinkerator hot water heater is no longer made, and if so you must be considering some other electric hot water heater, which may or may not be 1500 W.

If you want the flexibity to treat it like any other 110 VAC load, that works too as the wiring for those circuits get power from you house batteries through the inverter but get switched to the generator or shore power if either of those are available. Just make sure the switch on the heater is off when you don't want to heat water whenever the inverter is turned on and you are not on shore power or generator.

Off the grid while camping I use a rheostat on the water heater so I can heat water at say 750 W instead of 1500, not because 1500 W would be taxing the inverter's 2000W continual use power limit, but because I wanted to have the freedom to turn on the 750 W microwave and other lesser power hungry things like lights, propane heater fan or sound system while the heater cycling on and off. Note I also have 300 AH of battery, so heating the 2.5 gal of water which take about 15 min at full power and therefore uses about 30 AH or about 20% of usable battery power. In the summer the solar system can easily put that back in the batteries in part of a day.

Our van came with the Extra Heavy Duty 140 Amp alternator, but at 1500 W (125 A @ 12 V) that is too much of a load in my opinion especially on a diesel to heat water while driving to have hot water in route and/or ready to go right after pulling into camp. Thus the rheostat. This assumes (I really don't know) that while driving the inverter is supplied by the house batteries, but the alternator is trying to charge those batteries plus other usual things like two engine batteries, injectors, lights, etc., and it seems the alternator might have problems keeping up with too many things needing juice.

[photographix]

Our van has the Insinkerator W-152, but the PO let it freeze last winter. He suspected that the bronze tank cracked, but I haven't taken it out of the van yet to verify if that is the exact problem.

If it is the tank, I can't find a replacement tank anywhere online, and also it seems that the unit is discontinued.

Anyone know what is SMB using for 110v water heaters these days?

[coyotearms]

Originally Posted by photographix

Anyone know what is SMB using for 110v water heaters these days?

Why don't you just call one of the SMB facilities or Google for a replacement? It may be difficult to find something other than a hot water dispenser (~200 degrees), but the key, I think, is making sure the thermostat has a range similar to a regular home hot water heater, i.e. something like 110 to 150 or higher degrees. Off the grid I like to have it set low, and when plugged in higher (I drilled a hole to more easily tweak it (see another post on this thread).

Alternately, I have started to use our induction hot plate to heat a pot of water or sometimes just bring a 110v hot water pot (the cordless ones are convenient). That way you can heat just the amount of water you need quickly electrically with no standby losses. Those methods work well when the amount of solar is iffy. My last choice is a pot of water on the propane stove due to all the moisture it creates. But redundancy is a good thing!

After having the van for a couple of years now, I think life without a built-in hot water tank would definitely not make a big dent in convenience given the alternate methods suggested above. It is convenient when plugged in, but off the grid our 15 gal fresh water tank is not large enough to take outside showers anyway. If it warm enough for an outside shower, we use a solar shower, i.e. the one of those bags with a shower head you lay in the sun for a bit and then hang up.