LAARS Mighty-Stack TL80-199 - Installation, Operation and Maintenance Instructions - Manual (Page 17)

Mighty Stack Water Heater Page 17
SECTION 3.
Maintenance and Service
WARNING
Follow local regulations with respect to installation
of carbon monoxide (CO) detectors. To reduce the
risk of CO spillage, follow the maintenance
schedule for the water heater.
3A. Regular Maintenance
Do this immediately after installation
• Inspect the external surfaces of the heat
exchanger for fouling. This could indicate a
problem with the supply of combustion air.
Inspect again on this schedule:
–
24 hours
– 7 days
– 30 days
– 90 days
– Once every six months thereafter
• Keep the area around the water heater clear.
Remove any combustible materials, gasoline, or
any flammable vapors and liquids.
• Be sure that all openings for combustion and
ventilation air are not blocked.
Do this at least once a year
• Have the unit inspected by a qualified service
technician. See Section 3B.
• Lubricate the water circulating pump. Follow the
instructions supplied with the pump.
• If a strainer is employed in a pressure reducing
valve or the piping, clean it.
• Check the burner and pilot flames (see Figure
14). Do this at start-up, and check regularly
afterwards. If the flame has “sooting” tips, check
for debris near the orifices. If the orifices are
plugged, call a service technician to correct the
problem.
• Inspect the venting system for obstructions,
leakage or corrosion.
• Drain a few gallons of water out of the bottom of
the tank. This will remove any sediment which
has collected.
3B. Recommended Annual Inspection
The gas and electric controls on the water heater
are engineered for long life and dependable operation.
All of the controls and safety devices must be working
correctly for the unit to operate safely. Laars strongly
recommends that the basic items listed below be
checked by a qualified service technician
every year.
• Change sacrificial anode
• Water temperature controls
• Pilot safety system
• Automatic gas valves
• Pressure switch (inducer fan proving switch)
• Inducer/blower assembly
• Check function of temperature and pressure
relief valve
• Check/clean screen in flue collector assembly
NOTE: The warranty does not cover damage
caused by lack of required maintenance, lack of water
flow, or improper operating practices.
3C. Cleaning the Heat Exchanger
If the heat exchanger must be cleaned, follow
this procedure:
1.
Shut off all power to the water heater.
2. Remove the venting top, flue collector, draft
inducer assembly, and heat exchanger baffles.
3. Remove the burner tray.
4. Clean any soot and loose scale from the outside
of the heat exchanger. Use a hand-operated spray
bottle filled with water, and a wire brush. Do not
use compressed air, high-pressure water, or a
garden hose. (This could damage the
combustion chamber.)
5. Clean out any debris which has fallen to the
bottom of the unit.
6. Check to make sure the burner ports and the pilot
assembly are free of debris before returning the
burner tray to its original position.
7. Reassemble the water heater in the reverse order.
Be sure to replace the baffles in the heat
exchanger.
3D. Operating Sequence
Figure 2 and Figure 12 show the locations of the
parts and sensors used on this heater.
1.
At the beginning of the cycle, the tank contains
heated water. The tank aquastat is satisfied, so
the burner is not firing.
2. When a hot water tap is opened, hot water is
drained from the tank. This is replaced by cold
water, which enters the bottom of the tank.
3. There is an aquastat mounted near the bottom of
the tank. Eventually the water temperature at the
aquastat drops below the set point, and the
aquastat calls for heat.
4. When the aquastat calls for heat, the tank
circulator starts. (Notice that this happens before
the burner lights.) The water circulates through
the tank, and through the heater.