54(1) Open a hot water fixture and confirm that the Burner On lamp comes on, and that hot water isbeing produced. (If necessary, repeat until the air in the gas piping is bled out).* White smoke may be noticed from the exhaust vent during cold weather. However, this is not amalfunction of the unit.* If an “11” error code appears on the remote controller, turn the unit off and then back on again,and then open a hot water fixture again.(2) Change the temperature setting on the remote controller and check that the water temperature changes.• If the water heater does not operate normally, refer to “Troubleshooting” in the Operation Manual.* After the trial operation, clean the filter in the cold water inlet.• Turn the system power on with the remote controller.• Slowly open a hot water fixture and check that the units ignite sequentially. Check to see that thehot water temperature is the same as the temperature displayed on the remote controller. (*1)* If both units do not ignite, switch which unit will ignite first by pressing the Max. or Min. Mani-fold Pressure Set Button on the circuit board (see p. 57). (*2)* If an 11 or F11 error code flashes on the remote controller, hit the Power Button on the remotecontroller off and on 2-3 times.* If (*1) and (*2) cannot be done, the Quick Connect Cord may not be properly connected.Check that the cord is properly connected.13. Maintenance Periodically check the following to ensure properoperation of the water heater.• The venting system must be examined periodically by a qualified service technician to check forany leaks or corrosion.• The burner flame must be checked periodically for a proper blue color and consistency.• If the flame does not appear normal, the burner may need to be cleaned.• If the burner needs to be cleaned, it must be performed by a qualified service technician.• Do not obstruct the flow of combustion and ventilation air.• The pressure relief valve must be operated once a year to ensure that it is functioning properlyand there is no obstruction. Turn the power off to the unit before opening the relief valve, andmake sure that water draining out of the valve will not cause any damage.• If the relief valve discharges periodically, it may be due to thermal expansion in a closed watersystem.• Contact the water supplier or a local plumbing inspector on how to correct this situation. Do not plugthe relief valve. See Operation Manual for further maintenance.Warning: There is a scald potential if the output temperature is set too high.Should overheating occur, or the gas supply fail to shut off, turn off the manual gas control valve to the appliance.Do not use this appliance if any part has been under water. Immediately call a qualified servicetechnician to inspect the appliance and to replace any part of the control system and any gas controlwhich has been under water.Periodically check and clean the filter inside the cold water inlet of the unit.14. Trial Operation The installer should test operate the unit, explain tothe customer how to use the unit, and give the ownerthis manual before leaving the installation• Preparation ........... (1) Open a hot water fixture to confirm that water is available, and then closethe fixture.(2) Open the gas supply valve, turn on the power supply, and press the PowerOn/Off button on the remote controller (the Operation lamp will turn on).Unit A IgnitesUnit B Doesn't IgnitePress Max. or Min. ManifoldPressure Set Button on Unit B Unit A Doesn't IgniteUnit B Ignites