Tempering Valve - Aqua-Hot 400 Series Service Manual

Tempering Valve:

The tempering valve for the Aqua-Hot mixes the heated do-
mestic water from the boiler tank with cold domestic water
at pre-set ratio to reduce the risk of scalding.
Troubleshoot the tempering valve if the following condition
has occurred:

There is a lack of hot domestic water.

If domestic hot water is too hot.
Troubleshooting:
1. Inspect the tempering valve to ensure that it is not leak-
ing,
2. Test the temperature of the hot water using a digital
thermometer at one of the hot water faucets. Water
temperature should range between 115°F to 123°F. If
the proper range cannot be set, follow the instruction in
this section to replace the tempering valve.
3. Test the tempering valve's functionality by turning the
knob.
4. While running water, if the inlet pipe is excessively hot
while the outlet is lukewarm and adjusting the mixer
valve results in no change, it may be a faulty mixer
valve.
If the tempering valve's knob does not turn freely, follow the
instructions in this section to replace the tempering valve.
NOTE: Prior to troubleshooting the tempering valve, it is
recommended to review the Lack of Hot Water Trouble-
shooting Guide.
Figure 18
Replacement Procedure:
Failure to disconnect all power supplies and/or to allow the
heater to cool before servicing could cause serious damage
or personal injury.
1. Turn off the motor home's water supply.
2. Drain the water pressure by opening the faucets and
allowing the water to drain.
3. Disconnect the motor home's water lines from the tem-
pering valve assembly.
4. Disconnect the pex pipe and fittings from the tempering
valve assembly.
5. Remove the pressure relief valve assembly from the
tempering valve assembly, as the tempering valve can-
not be removed from the Aqua-Hot with the pressure
relief valve attached.
6. Using a back up wrench, unscrew the tempering valve
from the Aqua-Hot.
Failure to use a backup wrench could result in damage
to the cold water inlet pipe.
7. Remove the brass fittings from the defective tempering
valve.
8. Install the brass fitting onto the replacement tempering
valve. Use thread seal on fittings.
9. Install the replacement tempering valve onto the Aqua-
Hot using the back-up wrench to tighten.
10. Install the pressure relief valve onto the replacement
tempering valve. Use thread seal tape.
11. Reconnect the pex pipe and fitting on the tempering
valve and the Aqua-Hot. Be sure to inspect the rubber
seals and replace if necessary.
12. Reconnect the motor home's water lines to the temper-
ing valve assembly.
13. Turn the motor home's water supply back on and check
for leaks and the presence of hot domestic water.
14. Verify that the replacement tempering valve has been
set to the proper setting by taking a digital thermometer
to the hot water faucet and set the water temperature
between 115°F to 123°F.
© Aqua-Hot® AHE-400-P01 Service Manual Rev.B June 2014
Section #: Title
Aqua-Hot Components
p.
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