18 | Troubleshooting
Water flow too low
There are restrictions
Obstructions in the water path can restrict the flow of water through the heater. Verify the heater's inlet
in the plumbing
filter screen, faucet aerators, showerheads and whole house filters are clear of debris. Verify proper flow
on the outlet side of the heater with the hot water pipe disconnected. Maximum flow rates for each unit
are as follows. WH36 = 5.0gpm.
Water supply pressure
Verify incoming water supply is at least 14.5psi. For people on well systems, the recommended
too low
pressure range is 30-50psi.
Outlet shut-off valves
Adjust installer supplied outlet valve as described below:
are set too low
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Table 13
Water Temperature too Hot
Temperature dial set too
high
There are restrictions in
the plumbing
Inlet water temperature is
too warm
Table 14
Water Temperature fluctuates
Cold mix, heater deactivates
Fluctuating water pressure
Changing flow rate.
Water supply connected to the
outlet of the unit.
Table 15
6 720 647 022 (2014/06)
Completely open both installer supplied inlet and outlet shut-off valves at the heater. (if none
installed, install before proceeding).
Completely open hot water on the highest flowing hot water fixture served by the heater (i.e.
bathtub).
Slowly close the outlet shut-off valve, slowing the water flow rate until the temperature at the hot
water faucet corresponds to the values given on Fig. 8 of the manual, or desired water temperature
is reached.
Turn the temperature knob located on the bottom of the water heater counterclockwise for cooler
temperatures.
Obstructions in the water path can restrict the flow of water through the heater causing overheating.
Verify the heater's inlet filter screen, faucet aerators, showerheads and whole house filters are clear
of debris. Verify proper flow on the outlet side of the heater with the hot water pipe disconnected.
Opening hot water isolation valve fully may be necessary. Maximum flow rates for each unit are as
follows, WH36 - 5.0gpm.
Verify the heater is being feed with cold water only. This water heater is not designed for preheated
water or recirculation applications. Increase flow rate where ever possible. Replacing low flow
showerheads and aerators with higher flowing (GPM) ones may be necessary.
If inlet water temperature is over 70°F, water may be very hot out of the tap. This requires a lot
of cold water to be added in order to get a usable hot water temperature. The addition of too
much cold water will overpower hot water demand from the water heater. This slows the flow
within the water heater, decreasing it below the activation point, which shuts off the heater.
The end result is nothing but cold water coming out of the outlet. Increase the flow rate by
cleaning or replacing fixtures and lower the setting on the temperature adjustment knob.
If the water pressure in the home is erratic and the water flow is not consistent while a tap is
opened, then the temperature of hot water will fluctuate. The minimum water pressure for the
home should be 30psi or greater. For people on well systems the minimum pressure range is
30-50psi. The use of a pressure reducing/regulating valve is an effective way to maintain
constant water pressure to the water heater. Watts brand 25AUB- ¾" or N35B-¾" pressure
reducing/regulating valves or equivalent is suggested.
Major changes in flow rate can adversely affect the output water temperature of the heater.
Increases from one major fixture running to multiple fixtures running at one time can cause the
temperature to fluctuate. Stay within the heater's specifications. See Fig. 8.
Tronic 5000C