# tankless water heaters

Registered Users Posts: 18
I'm new to all this been reading untell my eyes burned out i understand the load dump to 12v to 48v water heater elememts to temper the water has any one tried putting 12v to 48v elements in tankless water heater and running it after you have tempered the water !! ??

• Registered Users Posts: 18
Re: tankless water heaters

They take alot of amps 35 to 54 for each element by not gonig through a inverter wire to the batterys would it work
• Registered Users Posts: 18
Re: tankless water heaters

This is the inside of one the pos. wires go straight to the elements the gound has a air temper shout off switch on each element the board in low voltage
• Solar Expert Posts: 10,300 ✭✭✭✭
Re: tankless water heaters
dulley wrote: »
I'm new to all this been reading untell my eyes burned out i understand the load dump to 12v to 48v water heater elememts to temper the water has any one tried putting 12v to 48v elements in tankless water heater and running it after you have tempered the water !! ??

i'm not sure what it is you are asking here. are you asking to put 12v to a 48v dump load? if so it won't work well by ohm's law. 1/4 of the voltage would also mean 1/4 of the current and thusly 1/8 of the power dumped. this is why they have different voltage ratings so as to utilize the power better.
• Registered Users Posts: 18
Re: tankless water heaters

1 = Cotroller load dump to 12v , 24v or 48v element or elements in a water heater tank so it tempers the water
2 = Wire two 12v , 24v or 48v elements you put in the tankless water heat straight to the batteries

By tempering the water the elements in the tankless water heater would not have to work so hard and would give you high water temperature
• Solar Expert Posts: 3,145 ✭✭✭✭
Re: tankless water heaters

Hi Dulley,

!. Bosch makes a tankless "booster" water heater, which can accommodate input water which has been heated by aonther source, such as solar water collector., it runs on GAS tho.

Guess that you are considering an electric tankless water heater, which has HUGE demands for electricity. Think that you might be happier with a tank type electric heater.

I have considered using an electric water heater as a PV DC Dump load -- running my 106 VDC PV array output into this electric tank type heater via a relay, which could be activated by the charge controller being in float stage, where, normally, lotta excess power is available. Have also considered running the output water from this electirc heater into a gas water heater, which might only run its burner when the incoming water was below its set point ... but for now, am using a gas tank type heater, simpler.

2. Niel,

Think there is a typo in you post: The power delivered to lower voltage heating elements is even worse ... 1/4 X 1/4 = 1/16 -- one sixteenth of the rated power ... you are right, very tepid heating.

Have fun Dulley, let us know how your heater works. Vic
Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
• Registered Users Posts: 18
Re: tankless water heaters

This is the element that i am going to try it is a 12v 600 watt it will take 30 35 amps i am just starting to get the parts togather to build my system and will post back it will be a year or so
• Registered Users Posts: 18
Re: tankless water heaters

I live high in the mountians of up state new york and the winter are long and cold and the summers are short
Re: tankless water heaters

You can get dump/diversion load heaters for hot water tanks that are 12v, 24v, and 48v rated... So that is available (around \$115 to \$85 each for 300-1,800 watts each, depending on wiring and voltage/model).

You would not usually put these heaters inside of a demand hot water heater--but in a standard electric tank water heater and temper the incoming water (assuming the demand heater can take variable input water temperature--like preheating for a second standard gas/electric water heater or the Bosch solar ready gas demand heater).

You can take a normal electric hot water heater and wire the top heater to grid power and change the lower element to a low voltage diversion type heater--and use one water heater for both functions (assuming you only need ~10 gallons of hot water at a time that is heated by the top tank grid timed heater).

In any case, there are some issues... #1 demand electric hot water heaters are usually only for Grid Power (unless you have a huge battery/inverter system). #2 demand electric hot water heaters usually cause annoying flickering of house lights (on/off cycling of heavy load). #3 If you use a tempering tank--you should have a tempering valve to make sure you don't get scalding hot water if that tank gets very hot. #4 you should have a second diversion load if the first hot water heating load hits high temperature limit to protect the wind turbine from overspeed (if needed). #5 you should have at least one redundant diversion load & controller in case the other fails (if needed for overspeed protection).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 18
Re: tankless water heaters

Just to let you guys and gals know I am form the dark side we rewire modify make ower own programes to reprogram everthing and anything so high and low voltage dc ,ac and chips are nothing new to me
• Solar Expert Posts: 10,300 ✭✭✭✭
Re: tankless water heaters

"2. Niel,

Think there is a typo in you post: The power delivered to lower voltage heating elements is even worse ... 1/4 X 1/4 = 1/16 -- one sixteenth of the rated power ... you are right, very tepid heating."

good catch as you are right. i was thinking 24v to 12v not 48v to 12v. still, my general message is understood, but i still am unclear what dulley has in mind.