Periodic Cleaning Of Heat Exchanger; Strainers - Inspection And Replacement; Oiled Bearing Circulators; Check Water Heater Relief Valve - A.O. Smith APW015DW Installation & Service Manual

9
Maintenance

Periodic cleaning of heat exchanger

For a detailed description of the following
maintenance tasks, reference the CD provided with
the unit:
• De-scaling the heat exchanger
• Heat exchanger replacement

Strainers - inspection and replacement

The strainers are installed upstream of the energy source
shutoff valve for the main traps. These strainers must be
blown down periodically (approximately every three (3) to six
(6) months) to prevent the build up of any sediment.
The combination of electricity and water
⚠WARNING
can pose a very dangerous situation. Turn
off / disconnect all electric power before
attempting any maintenance procedure.
1. Follow Steps 1 through 5 of the shutdown procedure
(page 26) to take the unit off-line before attempting to
replace the energy source strainers.
2. The location of the strainers can differ between packages.
3. Carefully break the line connections on the inlet side of
both strainers.
4. Carefully break the line connection on the outlet side of
the strainers.
5. Remove and examine the strainers.

Oiled bearing circulators

1. The circulator shipped with the APW water heater is
water-lubricated. No oiling is required.
2. Check other circulators in the system. Oil any circulators
requiring oil, following circulator manufacturer's
instructions. Over-oiling will damage the circulator.
Figure 9-1 Domestic Water Side - Partial View
DOMESTIC WATER STRAINER
W/BLOW-DOWN VALVE
ISOLATION VALVES
(4 PLACES)
BOILER WATER STRAINER
W/BLOW-DOWN VALVE
DIR #2000577647
28
Indirect Plate Water Heater Installation & Service Manual

Check water heater relief valve

1. Inspect the relief valve and lift the lever to verify flow.
Before operating any relief valve, ensure that it is piped
with its discharge in a safe area to avoid severe scald
potential.
proceeding further.
⚠WARNING
⚠WARNING
2. After following the above warning directions, if the relief
valve weeps or will not seat properly, replace the relief valve.
INLET RTD
Ensure that the reason for relief valve weeping is the valve
and not over-pressurization of the system due to expansion
P & T RELIEF VALVE
tank waterlogging or undersizing.
OUTLET RTD
Read Section 3 - Hydronic Piping before
Safety relief valves should be re-inspected
AT LEAST ONCE EVERY THREE YEARS,
by a licensed plumbing contractor or
authorized inspection agency, to ensure
that the product has not been affected by
corrosive water conditions and to ensure
that the valve and discharge line have not
been altered or tampered with illegally.
Certain naturally occurring conditions may
corrode the valve or its components over
time, rendering the valve inoperative. Such
conditions are not detectable unless the
valve and its components are physically
removed and inspected. This inspection
must only be conducted by a plumbing
contractor or authorized inspection agency,
not by the owner. Failure to re-inspect the
water heater relief valve as directed could
result in unsafe pressure buildup, which can
result in severe personal injury, death, or
substantial property damage.
Following installation, the valve lever must
be operated AT LEAST ONCE A YEAR to
ensure that waterways are clear. Certain
naturally occurring mineral deposits may
adhere to the valve, rendering it inoperative.
When manually operating the lever, water
will discharge and precautions must be taken
to avoid contact with hot water and to avoid
water damage. Before operating lever, check
to see that a discharge line is connected to
this valve directing the flow of hot water
from the valve to a proper place of disposal.
Otherwise severe personal injury may result.
If no water flows, valve is inoperative. Shut
down the water heater until a new relief
valve has been installed.