On demand water heater installation

It appears you need higher amperage than is designed for RVs in order for on-demand water heaters to work well in shower environments. I really wanted to look into this, considering that I'm a woman with long hair. I just have to shower twice, once for my hair, and second for my body. Fortunately, given my farm lifestyle, I only do the former about twice a week and the latter every day, just a five-minute rinse down to warm up or cool down, depending on the time of the year.

I do not believe an electric on demand water heater is practical in an RV, unless it is a 50 amp rig, and you don't mind spending more than half of that capacity on hot water. Most I have seen are 30 amp/240 volt units- 20 amps at 120 volts just is not going to heat water on demand very well.

Looking- a 3400 watt 120 volt model only gives a 35 degree rise at .7 gpm- not enough for a shower to me, just enough for hand washing.

jlegere wrote:
not exactly sure but the device that will take priority will be an on demand electric water heater. the secondary will be the a/c unit so a 20 will take care of that side.

It's really hard to help not knowing what you need amp wise.

not exactly sure but the device that will take priority will be an on demand electric water heater. the secondary will be the a/c unit so a 20 will take care of that side.

jlegere wrote:
that is exactly what is needed, but in higher amperages.

What amperage are you trying to shift? They make the same device in 30 Amp.

that is exactly what is needed, but in higher amperages.

I think what you need is a 20 Amp Automatic Load Shed Device. You just set the one that you want to be priority. Some RV's have an Engery Manage System that does the same.

A 20 Amp SPDT (3 Way) switch will do the job for you.

Not high tech and cheap (under $10.00 for parts).