installing a extra electric water heater

[sledhead]

I would like to install a extra small 2.5 gal electric water heater for my wife so she can have more hot water when in the bath .
the problem is location location location . I do not have enough room to put it beside the gas elect. heater I have now. So I was thinking of installing it in my water bay which is one bay back from my gas w/h . I was thinking of

#1     piping the cold to the first w/h then the hot from the first to the second cold inlet ( like a preheat ) I have done this before      when the hot water run is to far away . Works great

# 2    what if I installed each separate so each w/h would have it's own cold supply with each water heater going into the hot water line  ...... has this ever been done ....   sounds kinda dumb  but I don't know 

thanks   dave 

[mung]

Why not go with an on demand water heater?

[HB of CJ]

I think demand type water heaters, be they electric, propane, diesel or natural gas all still require some serious venting?  Also the electric types use a lot of power, thus amps or watts, thus requiring either serious hook ups or a gen set or a big inverter and battery bank?

However, having said that, the elegance of having nearly unlimited hot water until the battery bank runs down seems like a very nice idea indeed.  I am now wondering if a small electric instant hot water heater, a big inverter and a bigger battery bank would work?

Particularly this time of year?  Oh yeah!  HB of CJ (old coot)

[Iceni John]

Or could you crank up the hot water temperature to its maximum (assuming it's not so already), then you would mix it with more cold water, resulting in more bath/shower temperature water?   As long as you don't have children etc using the water, there shouldn't be any danger of scalding if everyone knows that the hot water is VERY HOT.

As an adjunct to this, I'm thinking of making or buying some solar water heating panels that could do one of two things  -  either preheat the cold water into the heater to reduce the time it needs to run (hence reducing propane costs), or warm the cold water for the entire bus so it will make the water heater's hot water go further when mixed to usable temperatures.   Either way, what's not to like?   Drinking water will still come from the fridger, regardless of its original temperature.

John

[luvrbus]

A good thermostatic mixing valve with the temp turn high on the water heater would probably do more good than a 2.5 water heater IMO

[Oonrahnjay]

A good thermostatic mixing valve ... 

      Yeah, I use one - seems to work well.  Most places around here, you have to ask for a "tempering valve" for people to know what you're talking about.

[pabusnut]

I mounted one of the el-cheapo instantaneous lp gas hot water heaters in the bathroom above the back of the toilet(now not for tall people  ), and it works very well---up to a point.  I found out that in the mountains of North Carolina, where the incoming RV park water is nearly freezing, the water heater almost heats it to lukewarm--so either winter camping is out, or my system needs some modifications.

Steve Toomey

[sledhead]

I have used the on demand gas water heaters on 2 separate homes and both times I took them out due to the fact that you used a lot of water just waiting for hot water . I have not tried a r/v on demand unit but I think it would be worse . I will give it a try turning up the temp. on the water heater I have now . I am going to try the remote bay to bay using the hot from 1 to the cold on the other . The house I have now has a boiler unit that heats my floor and heats the water in the hot water tank that feeds hot water to a small 12 gal. w/h that is elect. 60' away in a closet behind the 2 bathrooms . No wait at all for hot water . I was looking for a alternative as the 10 gal. r/v unit is fine for showers but the boss would like a little more water in her bath .

dave     

[Oonrahnjay]

I have used the on demand gas water heaters on 2 separate homes and both times I took them out due to the fact that you used a lot of water just waiting for hot water . ... 

      I have an on-demand propane hot water heater (Rinnai - not sure of the exact model) in my house.  It was installed about spring 2011.  I had to dig out the paperwork and flip a "dipswitch" to set it to maximum hot but once that was done, it has been perfect.  I turn on the shower and before I can get my socks took off, it's HOT.  But I have to pretty much slam the water to "On" when I turn it on, otherwise, it acts a little lazy.  But if I do that, it is very good and very economical on the propane.
      Got no idea how it would work on bus water pressures, and g/minute usage. 

[Homegrowndiesel]

Stick a proheat, or webasto in there. add a heat exchanger, and have constant hot water on demand.

[oltrunt]

I have an Ecotemp instant hot water heater in my little bus.  I put a recirculating circuit on it operated by a solenoid.  A flip of a switch starts the water flowing through the heater and then back to the tank.  After a few seconds I turn the faucet on and the solenoid off and have plenty of hot water with no waste.  Jack

[scanzel]

In my conversion I installed an Indel marine stainless 20 gallon electric hot water heater with the additional loop for my Proheat and my wife never runs out of hot water. When my wife showers she comes out looking like a Maine cooked lobster all red but she loves it, too hot for me.

[mung]

Electric point of use heaters do not need any venting and will get you hot water faster than pulling from a tank.  They draw a lot of power, but if you are not using it as your primary source of hot water when boondocking you should be fine.  At a campsite, who cares how much power it draws as long as it doesn't push you over the edge for total current draw. 

I run propane whole house units in my house and with the exception of my incoming water being high in temp as well as living in an old house with small hot water pipes, everything has been great.  It is just a little finicky with the settings.   

[TomC]

I use 2-10gal electric water heaters straight from HD. No heat exchangers. One feeds into the next with the final water heater powered through the inverter for hot water while driving. All that is needed is to run the generator for about 2 hours in the morning (to charge batteries also). Both water heaters can heat in 45 minutes from cold. The two water heaters in my bus have been in use for 20 years with no maintenance, except a yearly drain (when I remember). I like the system so much, I'm repeating it in my truck. Simple. Good Luck, TomC

[sledhead]

Hi Tom

do you feed the inverter 1 with the hot water line from the 2nd w/h ? so when using only the 1 w/h the cold water pass's through the first w/h then to the second 

thanks dave