Temperature-Pressure Relief Valve Test; Draining And Flushing; Sediment Removal; Lime Scale Removal - Lochinvar 100 Series Instruction Manual

7. Reinstall the top plug.
Refill the tank. See Filling The Water Heater (page 17).
8.
9. Turn on the electrical power supply and restart the water heater
See Start Up and Operation (page 17).

TEMPERATURE-PRESSURE RELIEF VALVE TEST

The temperature-pressure relief valve must be manually operated
at least once a month. Lift the lever at the top of valve several times
until the valve seats properly and operates freely. See Figure 9.
When checking the temperature-pressure relief valve operation,
make sure that (1) no one is in front of or around the outlet of the
temperature-pressure relief valve discharge line, and (2) that the
water discharge will not cause any property damage, as the water
may be extremely hot. Use care when operating valve as the valve
may be hot.
Figure 9. Testing the T&P Relief Valve
If after manually operating the valve, it fails to completely reset and
continues to release water, immediately close the cold water inlet
to the water heater, follow the draining instructions in the Start Up
section of this manual, and replace the temperature-pressure relief
valve with a properly rated/sized new one.
If the temperature-pressure relief valve on the water heater weeps
or discharges periodically, this may be due to thermal expansion.
Consult your local water supplier or a Qualified Service Agency for
further information. Do not plug the temperature-pressure relief valve.

DRAINING AND FLUSHING

Draining the Water Heater
It is recommended that the water heater storage tank be drained and
flushed every 6 months to reduce sediment buildup. The water heater
should be drained if being shut down during freezing temperatures.
Maintenance and service procedures may also require draining the
heater See Features and Components (page 8) for the location of
the water heater components described below.
1. Turn off the electrical supply to the water heater at the breaker
or disconnect switch.
2. Ensure the cold water inlet valve is open.
3. Open a nearby hot water faucet and let the water run until the
water is no longer hot.
4. Close the cold water inlet valve to the water heater.
5. Connect a hose to the water heater drain valve and terminate it
to an adequate drain.
6. Open the water heater drain valve and allow all the water to drain
from the storage tank.
7. Close the water heater drain valve when all water in the storage
tank has drained.
8. Close the hot water faucet opened in Step 3.
9. If the water heater is going to be shut down for an extended
period, the drain valve should be left open.
Follow FILLING instructions when restoring hot water service. See
Filling The Water Heater.
Flushing the Water Heater
The water heater drain valve should be opened periodically to help
prevent sediment buildup on the tank bottom.
1. Turn off the electrical disconnect switch.
2. Open a nearby hot water faucet until the water is no longer hot,
then close the hot water faucet.
3. Attach hose to outlet opening of drain valve and direct end to
drain.
• Open the drain valve by turning the hand wheel to the left
(counterclockwise). Allow water to flow until it runs clean.
• If water does not flow from opened drain valve, follow
instructions for sediment removal.
4. When finished flushing:
• Close heater drain valve and remove hose.
• Turn on electricity.

SEDIMENT REMOVAL

Water borne impurities consist of fine particles of soil and sand which
settle out and form a layer of sediment on the bottom of the tank. In
time, if not removed, the level of sediment might reach the heating
elements and cause their failure.
For convenience, sediment removal and element lime scale removal
should be performed at the same time as follows.

LIME SCALE REMOVAL

Lime scale accumulations on the heating elements is a normal
condition, common to all immersion type elements. Factors which
affect the amounts of this formation are:
Maintenance
• Burn hazard.
• Hot water discharge.
• Keep hands clear of drain
valve discharge.
Commercial Electric Water Heaters • 39