RTO American Heat Tankless Electric Water Heater - Answered Questions & Fixed issues

If you had a power surge at your home, and no more power seems to be going to the heater, you must make sure that none of your wires from the load center all the way to the heater are intact and all have been wired correctly and none are lose. If you must be very careful reading manufacturing dates as these dates are actually displayed backwards and the year is actually displayed as the month, you may in fact have an older heater, as sometime when these heaters are purchased by distributors they don't get to sell them until way after or they have had one in storage for a while when they decide to sell them. I have spoken to the guys at the factory and they are very informative, I don't see how they could not help you as I deal with them on a daily and we always try and help there customers, why don't you bring the heater in there service department is great it only takes 5 minutes to fix the heater. If you mail it in its only 24-72 hr turn around.

try these steps - hope it helps

• Selected temperature on your tankless water heater is too high. Select the lower temperature.
• Inlet filter is dirty... clean it.

• Make sure that there are no water path obstructions, including faucet aerators, shower heads...

• Is the heater using the specified gas type?

• Temperature sensors are loose... ensure that sensors are firmly mounted and are making contacts.

Hi,
The problem is usually the thermal saftey cutout switch....this can be manually reset, but if it continues to cutout then the thermostat is bad and needs to be replaced...

You can see all of the parts and where they are located by going here and checking out page 4

heatman101

You must to make sure that you have not used too much teflon tape, and also that the flow sensor is still inside the inlet pipe. For example these units some with a reed switch type flow mechanisim which when flow is detected it opens the door for the electricity to pass through the unit. so no Flow no power, or in your case there maybe something clogged, or your flow sensor is not inside the inlet pipe, also if this unit has been installed previously and had been working for sometime now, then check on the inside pipe behind the screen you will notice there is a small black or either white bullet style flow switch, if this flow switch is stuck on the inside of the unit, this is your problem, if not its a reed switch, you can call 1-888-818-4328 and ask for an ADK reed switch see picture attached

If you live in an area where you have hard water it can destroy pretty much any tankless water heater, but it seems that you may have another problem, I speak to them on a regular basis and everyone there seems to speak English and Spanish, its very important to make sure that this unit is installed by a liscensed person, whom will check your wire gauge, and breaker size, if you use 240v this unit can draw upto 66 amps, so its important to have an electrician size your heater for the correct voltage.

You need to get a real tankless water heater, I had one of this brand and what a waste of money, when you call the company they do not speak very good English and if you talk to Richard whom is supposedly the VP he is as dumb as a mule.

Possible causes and solutions:

1. Safety Thermal Cut-Out Tripped, Reset.
2. Not enough flow rate to activate unit, clean filter screen at unit, clean aerator at faucet.

I hope this has helped. Please rate the answer as to it's helpfulness. Good Luck and have a great weekend. Jeff

If there is only cold water coming out from the water heater, there is no doubt that your RTO water heater
is defective.
1. Shut the power supply going to your heater off.
2. You can check on it, by opening it up.
3. Trace the wires coming from the power supply.
Using a multitester, check the continuity of each
line. Set the tester to Ohms 1 x 10. Put the multi
tester probe to each end of the electrical line, one
line at a time. The pointer must point to zero.
Otherwise, it must be replaced.
4. Test the heater coil for continuity. One of the multi
tester probe must be placed at the common termi-
nal. Put the other probe to the other terminals. The
pointer must be at zero, otherwise, you can
replace the heater unit, since this is already
busted.

no the tub faucet is the only faucet that is wide open you might have to not run full blast on the faucet , your tankless water heater is under sized for the application, to many gallons per min going thru the unit, look at the rating chart for your unit, the r94 is only 9.4 gallons per min, and a tub faucet can be upto 5 gallons per min, depending on the faucet,,

The high limit should be on the top side of the unit near the exhause. Check your manual for location and to find out if it can be reset.

Mike Wenger

Owner Manuals

Bad faucet cartridge: walk-thru on following link http://waterheatertimer.org/Crossover.html If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

What water pressure reading do you have? IS there a mixer in the system? What is the exact model number?

no I dont think you have a mother board. If there wasone it would be in a box of some sort on the top or right near the top mounted on the side.

If you replaced the coupler, I would say the gas valve is bad. Go to you local supply store and get a new valve. you should have 3 connection on the valve, the main gas feed and the main burner and your coupler.

Make sure you turn off the water at the main, drain it all down and when you have all the connection moved get a large channel lock or pipe wrench and turn the valve counter clock wise use tape or dope on the section that goes into the tank and tighten it up, hook up your other pipes and test for gas leak with soap and water.

Make sure when you buy the valve you get a match to the kind of gas you have natural or L P one will not work with the other.

OH check for gas leaks

Best of luck Tom

First check and see if the dial on the gas valve is on the ON position. Next turn the thermostat up all the way.if it does not come on then, this sounds crazy, but, tap the gas valve twice lightly with the back end of a screw driver, sometimes a spec of dirt can clog the gas valve and this releases it. if it still doesnt come on, you need a Volt Ohms meter or multi meter, set the meter to millivolts, you want to connect the 2 leads from the meter to the terminals on the gas valve that the 2 wires from the pilot generator, located next to the main burner underneath tank. turn the meter on and the millivolts should read a minimum of 400 milivolts, if lower, replace pilot generator. If still doesnt work, replace gas valve.

That is not a model number that sounds familiar. Should be a tag on side of water heater behind cover, outside. If it has the little arm adjustment for temperature on top of gas valve, simply move it over a little to the left to increase water temperature, and try it until temperature is what you are happy with.
I'm assuming when you say it goes out completely that the pilot remains on and water heater re-lights when called for? If you adjust that temperature lever over, and water still doesn't get hot, you need to replace gas control, as thermostat is built in to it.

I am not sure they are available to non Hitachi service centres. https://documentation.hitachiaircon.com/glb/en/pac/rua-at3s

Cannot find the fault code . There are vidoes on u tube saying how to reset thr code By pressing the reset button . If this does not work youcan ccontact vaillent on there web page . I have a mate who works for them i will ask him as well

Do I need to insulate this heater out in the shed? Freezing temperatures

Call a engineer