Hubbell Electric Heater Company T - Manual (Page 13)

13
ANNUAL INSPECTION
1. Flush tank as follows
a. Shut off power supply.
b. Close valve on hot water outlet piping.
c. Open valve on drain piping.
d. Cold water inlet line pressure will be strong enough to flush sediment from the bottom of the
tank out through the drain. Let water run for 3-4 minutes.
e. Close drain valve.
f. Open hot water valve.
g. Turn power supply ON.
2. Units subject to fouling or scaling should be cleaned periodically. A marked increase in pressure
drop and/or reduction in performance usually indicates cleaning is necessary.
3. To clean inside of tubes, remove all heads and covers. (Caution: Do not loosen heads until you
are sure all pressure is off the equipment, and the unit is drained).
4. Clean the unit using the following methods.
a. Circulate hot fresh water at a reasonable velocity.
b. Try spraying with water hose.
c. Consult with manufacturers of cleaning compounds and chemicals. They will check the
nature of the deposit, recommend the right cleaning compound, and in many cases provide
equipment and personnel for a complete cleaning job.
5. If the unit is dismantled for any reason, it should be reassembled using new gaskets.
6. Do not tighten bolts until gaskets are properly seated.
7. When tightening bolts in the element head, tighten the bolts in a criss-cross pattern. This will
evenly distribute pressure around the flange, and help prevent warping.