• Read the temperature and pressure gauge to ensure the system
is pressurized. Minimum is 10 psi. Maximum is 25 psi. Lift the
relief valve top lever slightly, allowing water to relieve through the
valve and discharge piping.
• If water flows freely, release the lever and allow the valve to seat.
Watch the end of the relief valve discharge pipe to ensure that
the valve does not weep after the line has had time to drain. If the
valve weeps, lift the lever again to attempt to clean the valve
seat. If the valve does not properly seat and continues to weep,
contact a qualified service technician to inspect the valve and
system.
• If water does not flow from the valve when you completely lift the
lever, the valve or discharge line may be blocked. Immediately
shut the appliance down per instructions on page 2 and call a
qualified service technician to inspect the valve and system.
Check the Burner
Clean the exterior of the burner.
Flushing the CH Closed Loop Heat Exchanger
Flushing the heat exchanger is a complicated procedure that should only
be performed by a qualified service technician. It is recommended to flush
the heat exchanger annually if water hardness exceeds 12 grains per
gallon (considered extremely hard water). If water hardness falls below 12
grains per gallon it is recommended to flush the heat exchanger every two
to three years.
NOTE: Improper maintenance WILL VOID appliance warranty.
1. Disconnect electrical power to the appliance.
2. Close the shutoff valves on both CH supply and CH return lines (V1 and
V2). See Figure 53.
3. Connect one hose (D1, Figure 54) to the valve (V3) and place the free
end in a bucket. Connect one of the hoses (D3) to the circulation pump
outlet and the cold water inlet line to valve V4. Connect the other hose
(D2) to the circulation pump inlet and place the free end in the bucket.
4. Pour tankless cleaning solution into the bucket. Use an FDA approved
cleaner for potable systems on the heat exchanger. Place the drain hose
(D1) and hose D2 to the pump inlet in the cleaning solution.
5. Open service valves (V3 and V4) on the hot water outlet and cold water inlet lines.
6. Turn on the circulation pump. Operate the pump and allow the cleaning solution to circulate through the appliance for at least 1 hour
at a rate of 4 gallons per minute.
7. Rinse the cleaning solution from the heat exchanger as follows:
a. Remove the free end of drain hose D1 from the bucket.
b. Close service valve V4 and open shutoff valve V2.
c. Do not open shutoff valve V1.
d. Allow water to flow through the appliance for 5 minutes.
e. Close shutoff valve V2.
8. Disconnect hoses from lines. Properly dispose of used cleaning solution.
9. Remove the CH filter from the appliance and clean out any residues.
10. Repeat process on the DHW loop of the appliance.