My Rinnai tankless water heater keeps tripping the breaker then when turned back on, it begins to beep and displays a code 12. What is causing this? It is new and this is the first time any code came.

Chris Ballard

• 18 Answers
• Posted on Dec 31, 2008

SOURCE: Rinnai tankless water heater code 12

12 - Flame Failure or Poor Ground

1. Immediate code 12 is usually a defective gas valve, power supply problem, or defective fan motor wiring harness.

2. If code 12 occurs after a few seconds it indicates that proper operation was established, but then stopped unexpectedly.

3. Verify that fuel is being supplied to the unit.

4. Check for proper electrical ground. Unit must use a grounded power supply.

5. Check for flue blockage on inlet or exhaust.

http://www.foreverhotwater.com/service-codes.php

SOURCE: No hot water

The code # 11 is a code that warns of "no ignition" and the causes of this error code are too many to list. I would suggest that a qualified tech. perform a diagnostic test and repair.

This is not a task for the "do it yourselfer"

SOURCE: takes too long for hot water.

You need a recirculating line. You will have to hire a plumber to run a water line from the farthest fixture or to the fixture you are concerned about on the hot side and return it back to the water heater. this will cause hot water to constantly run throught the hot water line (via the recirculating line) and when you want to draw water from the fixture, you will already have hot water right at the line.
I know this works with standard tank water heaters, but it is a lil trickier with rinnai units(but very possible) if your plumber pleads the 5th and tries to sell you another unit call the Rinnai manufacturerand ask them how.

snap101

• 117 Answers
• Posted on Jul 29, 2009

SOURCE: this things beeping and flashing 12 everytime we

check the error codes on it by pressing the on off button for 2 seconds then while holding the on/off button press the up button this should display the last 9 error codes let me know what they are

SOURCE: Rinnai tankless water heater

LC is the error code that you get when you have limescale buildup in the heat exchanger. You need to flush your heat exchanger. If you have the manual for your water heater, use it. The manual to mine is attached. The procedure for flushing it is covered on page 12. I suggest that you have a certified Rinnai plumber perform this task as it requires a ciruclating pump and some hoses that you need to connect to your water heater. If you don't perform this task, it is possible that you will need to replace your heat exchanger and this is not something covered by Rinnai's warranty.