Rheem Commercial Power Direct Vent Water heater - Manual (Page 18)

D. BLOWER — Clean the blower periodically to remove any buildup of
lint or dirt. Remove the inlet plate and blow out any lint or dirt on the
wheel and on the screen of the inlet plate. Before operation, re-install
the inlet plate to the blower.
E. PRESSURE SWITCH — Inspect the inlet to the pressure switch and
the tubing for debris or blockage. Clean out the tubing periodically to
prevent buildup of debris.
F. EMERGENCY CUT-OFF — This water heater is equipped with a com-
bination thermostat/temperature limiting device (ECO) that should be
checked annually by qualified service personnel.
G. THERMAL CUTOFF SWITCH — Some units are equipped with a
thermal cutoff switch which will shut down the unit if the flue gas tem-
perature is above permissible limits. The switch is a manual reset
type.
label all wires prior to disconnection when servicing controls. Wir-
ing errors can cause improper and dangerous operation.
VERiFY PROPER OPERATiON AFTER SERViCiNg!
G. RELIEF VALVE — The Temperature and Pressure Relief Valve must
be free to operate properly. Check (at least once a year) by lifting the
handle fully and allowing several gallons of water to flush through the
discharge line. Make certain the discharged water is directed to a
suitable drain.
Before manually operating the relief valve, make certain no one
will be exposed to the danger of coming in contact with the hot
water released by this valve. The water may be hot enough to cre-
ate a SCAlD hazard. The water released should be directed to a
suitable drain to prevent injury or damage.
NOTICE: If the temperature and pressure relief valve on the water
heater discharges periodically, this may be due to thermal expansion
in a “closed” water system. Contact the water supplier or local plumbing
inspector on how to correct this. DO NOT plug the relief valve outlet.
H. TANK— Good maintenance requires that the tank be cleaned of de-
posits. Unless the water supply is soft (0 to 5 grains hardness), scale
or lime deposits will accumulate in the tank. Hard water scale is de-
posited at an increasingly high rate in proportion to increased water
temperature. Accumulation of these deposits may reduce efficiency,
and shorten the life of the water heater.
Any new installation should have a tank inspection program set up
initially for frequent inspection. The first inspection should be within a
six month period. Once the scaling tendencies have been established,
the inspection program can be modified to suit the water conditions.
Cleaning should be performed if the scale has accumulated above the
drain valve opening.
A wet-dry shop vac with a nozzle fashioned from 1” and/or 3/4” poly-
ethylene pipe makes a good tool for scraping and removing scale.
TO CLEAN OR INSPECT TANK:
1. Shut off gas valve and drain tank.
2. Remove tank clean-out cover on jacket and with pocket knife cut
and remove a circular plug of insulation the full size of jacket open-
ing.
3. Loosen nut on seal plate assembly enough to twist yoke sideways.
Hold assembly securely and push inward, then remove from tank.
4. Remove as much built-up scale from flue tubes and tank bottom as
practical. Do not attempt to clean so thoroughly that the tool used
damages the glass lining.
5. Clean the seal plate and install a new gasket. Wipe clean the inte-
rior surface of the tank that contacts the gasket. Reinstall the seal
plate and tighten in position. Fill tank with water and check for leaks.
If no leaks are found, install insulation plug and clean-out cover on
jacket and re-light the water heater.
If chemical lime dissolving cleaners are preferred, cautiously follow
the instructions supplied with the cleaner. DO NOT use a muriatic or
hydrochloric acid (HCl) base cleaner.
2. ANODE INSPECTION — The water supply in certain areas contains
very aggressive elements. In these areas, periodic inspection of the
anode is recommended to determine if replacement is necessary. The
anode(s) supplied in this water heater is slowly consumed , thereby
eliminating or minimizing corrosion and protecting the glass lined tank.
The anode(s) should be replaced when more than 6 inches (15 cm) of
core wire is exposed at either end.
3. SEASONAL OPERATION — If the water heater is to remain idle for an
extended period (60 days or more) the heater should be turned off. The
water heater and piping should be drained if they might be subjected
to freezing temperatures. It is recommended that the water heater’s
operation is thoroughly checked (by a qualified service technician)
before it is placed back in service. NOTICE: Refer to Hydrogen Gas
caution notation on page 16.
18
maintenance
DANGER !
CAUTION !