Tempering Valve - Aqua-Hot 200 Series Service Manual

Tempering Valve

Tempering Valve
Introduction:
The tempering valve of the Aqua-Hot mixes the heated
domestic water from the boiler tank with cold incoming
domestic water at a preset ratio to deliver steady hot water and
reduce the risk of scalding. It is recommended that you review
the "Lack of Hot Water Troubleshooting Guide" on Page 57 prior
to diagnosing the tempering valve.
Troubleshooting Condition:
Troubleshoot the tempering valve if the following conditions
have occurred:
• A lack of hot water.
• Hot water supply is uneven.
• Hot water is too hot.
• The D4 light is not illuminated.
Troubleshooting Condition:
1. Inspect the tempering valve to ensure that it is not
leaking.
2. Activate the burner and allow the unit to heat unit the
burner shuts off. This test cannot to be accomplished
with the electric element.
3. Open the hot water valve on an interior faucet without
a hot-stop and allow the temperature to stabilize at its
hottest point.
4. Using a meat thermometer, take temperature reading
of the water. It should be between 115°F and 120°F.
Be aware that a water source temperature of less
than 65°F may prevent hot water from reaching this
threshold.
5. Test the tempering valve's functionality by turning the
knob (see Figure 31). If the knob does not rotate, this
tempering valve will need to be replaced. On newer
heaters, it will be necessary to remove a black plastic
cap from the body of the tempering valve.
6. While running water, if the inlet pipe is excessively hot
while the outlet is lukewarm and adjusting the mixing
valve results in no change, it may be a faulty mixing
valve.
7. If adjustment of the mixing valve is able to effect
change in temperature, it must be continually adjusted
until the output range of the hot water is between
115°F and 120°F.
NOTE:
Adjusting the mixing valve beyond 120°F will result in a lack
of hot water and may result in scalding. Do NOT attempt to adjust
the tempering valve without assistance from Aqua-Hot Technical
Support or a qualifi ed Aqua-Hot technician.
p. 26 ©Aqua-Hot® 250 Series Propane Service Manual
Failure to disconnect all power supplies and/or allow
the unit to cool before servicing could cause serious
damage or personal injury.
Replacement Procedure:
1. Turn off the coach water supply.
2. Drain the water pressure by opening the faucets and
allowing the water to drain.
3. Disconnect the coach water lines from the tempering
valve assembly.
4. Disconnect the PEX pipe fi ttings from the tempering valve
assembly.
5. Remove the pressure relief valve assembly from the
tempering valve assembly.
6. Using a back-up wrench, unscrew the tempering valve
from the Aqua-Hot. Failure to use a back-up wrench could
result in damage to the cold water inlet pipe.
7. Remove the brass fi ttings from the defective tempering
valve.
8. Install the brass fi tting onto the replacement tempering
valve. Use thread seal on the fi ttings.
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 fi ttings onto the replacement
tempering valve. Use thread seal tape. Be sure to inspect
rubber seals and replace is necessary.
12. Reconnect the water lines to the tempering valve.
Tempering Valve Knob
Figure 31