Abnormal Sounds Come From The Unit - American Water Heater 160X3P Manual

•
Make sure that a check valve
is installed on the return line.
A malfunctioning or missing
check valve will cause a cross
connection, allowing cold water to
back-feed into the system.
•
Check that the filters on the cold
and return lines are clean.
•
Is the inlet water temperature
is too close to the set point
temperature. Verify by opening
multiple faucets and check to
see if the water heater operates.
If the water heater operates
this may indicate a seasonal/
geographic condition causing
warmer inlet water that is too
close to the water heater's set
point. The minimum input is
9,000 btu/h which means the
heater will not activate if the
energy input is below this. For
recirculation systems, review and
adjust the temperature differential
setting as necessary.
•
New installations only: Are the hot
and cold water connections to the
water heater reversed (hooked
up backwards)? Water flowing in
reverse through the heater will not be
detected by the flow sensor and the
water heater will not operate. See
"Checking for a Reversed Connection"
on page 30 for details on checking
for a reversed connection.
•
If the fan does not initiate at all and
it is verified that there is power to
the unit, the flow sensor may not
be working properly. Check the
flow sensor for proper impeller
functionality See "Checking the
Flow Sensor," page 32.
Abnormal sounds come from
the unit.
•
Check the fan for debris.
•
Check for blockages in the exhaust
vent and intake air line.
•
Check terminations for proper
clearances to ensure flue gases
are not being drawn into the
combustion air intake.
•
Check for proper gas supply
pressure and allowable pressure
drop.
•
Check the rating plate to ensure
that the correct gas type is applied
to the unit. NOTE: This water
heater's gas type is field convertible,
confirm the orifice installed matches
the gas type supplied. See Removing,
Replacing, and Verifying the Gas
Orifice Assembly on page 47.
•
Check the DIP switch settings for
vent length, altitude and gas type.
•
If you cannot identify the source
of this issue, contact the technical
service department.
On-Demand Water Heater Service Handbook for X3P Models • 9