Flushing the Heat Exchanger (Error Code: LC or 00)

An “LC” or “00” error code indicates the unit is beginning to lime up and must be flushed. Failure to flush the appliance will cause damage to the heat exchanger. Damage caused by lime build-up is not covered by the unit’s warranty. After flushing, reset the LC fault code by turning off the power to the unit and turning the power back on.

1. Disconnect electrical power to the water heater.

2. Close the shutoff valves on both the hot water and cold water lines (V3 and V4).

3. Connect pump outlet hose (H1) to the cold water line at service valve V2.

4. Connect drain hose (H3) to service valve V1.

5. Pour approximately 4 gallons of virgin, food grade, white vinegar or citric acid into pail.

6. Place the drain hose (H3) and the hose (H2) to the pump inlet into the cleaning solution.

7. Open both service valves (V1 and V2) on the hot water and cold water lines.

8. Operate the pump and allow the cleaning solution to circulate through the water heater for at least 45 minutes.

9. Turn off the pump.

10. Rinse the cleaning solution from the water heater as follows: a. Remove the free end of the drain hose (H3) from the pail.

Rinnai

Water Heater

b. Close service valve, (V2), and open shutoff valve, (V4). Do not open shutoff valve, (V3).

c. Allow water to flow through the water heater for 5 minutes d. Close service valve, (V1), and open shutoff valve, (V3).

11. Disconnect all hoses.

12. With (V4) closed, remove the in-line filter at the cold water inlet and clean out any residue. Place filter back into unit and open (V4).

In-line

Filter

V1 V2

Gas Supply

13. Restore electrical power to the water heater.

H3

V3

V4

5 gallon pail of virgin, food grade, white vinegar (or virgin,

food grade, citric acid).

 

KEY

3/4" Ball Valve

Pressure Regulator

 

3/4" Union

Circulating Pump

Check Valve

Boiler Drain Valve

Pressure Relief Valve

S Solenoid Valve

Cold Water Line Hot Water Line

H2

H1

Circulating Pump

16

VA Series Indoor LS Manual

Page 15 Page 17
Page 16
Image 16
Rinnai R98LSI-ASME, R75LSI, R94LSI, R50LSI installation manual Flushing the Heat Exchanger Error Code LC or, Circulating Pump
Page 15 Page 17

R50LSI, R94LSI, R75LSI, R98LSI-ASME, R98LSI specifications

The Rinnai R50LSI, R75LSI, R94LSI, R98LSI, and R98LSI-ASME are high-efficiency tankless water heaters designed for residential and commercial applications. Each model in this line-up boasts unique features and technologies that cater to varying hot water needs while emphasizing energy efficiency and reliability.

The R50LSI is the most compact option in the lineup, providing up to 5.1 gallons per minute (GPM) of hot water at a 35°F rise in temperature. It is an ideal choice for smaller households or apartments where space is a premium. It operates using a direct vent system, ensuring safe exhaust of combustion gases outside the home. The R75SLI, with a maximum output of 7.5 GPM, is suited for needs such as multiple showers running simultaneously, making it perfect for medium-sized homes.

Moving on to the R94LSI and R98LSI, these models provide even greater capacity and efficiency. The R94LSI offers an impressive 9.4 GPM flow rate, while the R98LSI reaches a peak of 9.8 GPM, supporting larger family requirements and ensuring hot water availability for multiple applications concurrently. Both models incorporate Rinnai’s advanced Circ-Logic technology, which allows users to set schedules for recirculating hot water, minimizing wait time and enhancing convenience.

For commercial applications, the R98LSI-ASME is a specialized model that includes the American Society of Mechanical Engineers (ASME) certification. This makes it suitable for larger facilities, such as restaurants, schools, and other institutions that demand a robust and efficient solution for comprehensive hot water needs.

All these models feature a user-friendly digital controller, enabling easy temperature adjustments and real-time monitoring. Moreover, their compact design means they can be installed in various locations, saving valuable space. The Rinnai tankless water heaters utilize a highly efficient condensing technology, resulting in a lower carbon footprint and reduced energy costs.

With a robust warranty program and the reliability that Rinnai is known for, the R50LSI, R75LSI, R94LSI, R98LSI, and R98LSI-ASME embody the pinnacle of water heating technology. These models not only provide the convenience of on-demand hot water but also contribute to energy conservation, making them an excellent choice for environmentally conscious consumers.
Top Page Image Contents