Installation Guide

WHL-648 Rev. 000 Rel. 002 Date 1.3.18
63
Have leaks xed at once by a qualied service technician. Failure to
comply could result in substantial property damage, severe personal
injury, or death.
Operate Pressure Relief Valve
• Before proceeding, verify that the relief valve outlet has been
piped to a safe place of discharge, avoiding any possibility of
scalding from hot water.
• Shut power o to the appliance. To avoid scalding, wait for
appliance to cool before operating the relief valve.
To avoid water damage or scalding due to relief valve operation, a
discharge line must be connected to the valve outlet and directed
to a safe place of disposal. This discharge line must be installed by
a qualied service technician in accordance with the appliance
installation manual. The discharge line must be terminated so as to
eliminate possibility of severe burns or property damage should the
valve discharge.
• If you notice ue gas leaking from the opening, this indicates
a dry condensate drain trap. If problem persists, contact a
qualied service technician to inspect the appliance and
condensate line and rell the condensate trap.
• If applicable, check the condensate neutralizer and ensure it is
full of condensate neutralizing marble chips.
Check the Air Vent
Loosen cap one counterclockwise turn to allow air vent to operate.
See Figure 54. If the air vent works freely without leaking, close the
valve by turning clockwise. If vent does not operate correctly, contact
a qualied service technician to replace the vent.
Check Primary and Gas Piping
• Remove the appliance cover and perform a gas leak inspection
following Operating Instructions, page 2, this manual. If gas
odor or leak is detected, follow procedures on page 2. Call a
qualied service technician.
• Visually inspect for leaks around the appliance water
connections and around the heat exchanger. Visually inspect
the external system piping, circulators, and system components
and ttings. Immediately call a qualied service technician to
repair any leaks
Figure 54 - Air Vent Detail
• Lift the relief valve lever. If water ows 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 qualied
service technician to inspect the valve and system.
• If water does not ow 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 qualied service technician to inspect the valve and
system.
• If relief valve seats properly, restore power to the appliance.
Observe operation for ve minutes and ensure it operates
properly.
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 qualied service technician. It is recommended
to ush 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 ush 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 shuto valves on both CH supply and CH return lines
(V1 and V2). See Figure 55.
3. Connect one hose (D1, Figure 55) 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 shuto valve V2.
c. Do not open shuto valve V1.
d. Allow water to ow through the appliance for 5 minutes.
e. Close shuto valve V2.
8. Disconnect hoses from lines. Properly dispose of used cleaning
solution.
9. Remove the CH lter from the appliance and clean out any
residues.
10. Repeat process on the DHW loop of the appliance.
Flushing the DHW Loop Heat Exchanger
Flushing the heat exchanger is a complicated procedure that
should only be performed by a qualied service technician. It
is recommended to ush 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 ush 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 shuto valves on both hot water outlet and cold water
inlet lines (V1 and V2). See Figure 56-A.
3. Connect one hose (D1, Figure 56-B) 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
Figure 55 - Flushing the CH Closed Loop Heat Exchanger