LAARS Mighty Therm2 MT2P (Sizes 500–2000 MBTU/h) - Install and Operating Manual - Manual (Page 21)

MT2P Pool Heater Page 21
The gas and electric controls on the appliance are
engineered for long life and dependable operation, but
the safety of the equipment depends on their proper
functioning. It is strongly recommended that a qualified
service technician inspect the basic items listed below
every year.
a. Ignition controls
b. Ignitors
c. Water temperature control
d. Automatic gas valve
e. Pressure switches
f. Blowers
7.2.1 Burners
Close main manual gas valve before proceeding.
Checking the burners for debris - remove the ignitor
inspection panels(s) and ignitor(s) and inspect the
burners through the ignitor hole(s) using a flashlight
to illuminate. If there is any indication of debris on
the burners that are visible, all the burners will need
to be inspected more thoroughly. Remove the screws
from around the front of the air box (large panel from
which the ignitor inspection panel(s) were removed),
and remove the large panel. Remove the gas manifold
assemblies and the burner panels. Inspect the burners.
Clean burners, if necessary, by blowing compressed air
from the outside of the burners into the center of the
burner. A dirty burner may be an indication of improper
combustion or dirty combustion air. Determine the
cause, and correct. Replace the burners in the reverse
order.
7.2.2 Filter
The filter used in the MT2P is washable with an
83% arrestance. Since the filter is washable, it will
only need replacement in very rare cases. If filter
replacement is needed, it should only be replaced with
a factory part. Inspect the air filter. If there is debris on
the air filter, remove it from the filter box, and wash
it with mild soap and water. Ensure that the filter is
completely dry before re-installing, in reverse order.
7.2.3 Gas Valves
The gas valves are designed to operate with
supply pressures of 4-13 inches w.c. (1.0 to 3.2 kPa).
To remove a valve, shut off 120-volt power and
the manual gas shutoff valve. Remove the top front
panel from the unit. Disconnect the wires to the valve.
Disengage the unions before and after the valve, and
remove the valve. Pull the pipe nipples from the inlet
and outlet of the valve, and clean the threads on the
pipe nipples for re-use. Apply pipe dope to the pipe
nipples (threaded joints should be coated with piping
compound resistant to action of liquefied petroleum
gas), and re-install in reverse order. Turn on manual gas
shutoff valve and 120 volt power and check appliance
operation and tightness of gas valve connections.
thermometer; spa or hot tub thermostats may err in
regulating water temperatures by as much as 4°F
(2°C).
• Persons with a medical history of heart disease,
circulatory problems, diabetes or blood pressure
problems should obtain their physician’s advice
before using spas or hot tubs.
• Persons taking medications which induce
drowsiness, such as tranquilizers, antihistamines or
anticoagulants, should not use spas or hot tubs.
SECTION 7.
Maintenance
7.1 System Maintenance
1. Lubricate the system water-circulating pump, if
required, per the instructions on the pump.
2. Inspect the venting system for obstruction or
leakage at least once a year. Periodically clean the
inlet air filter and the screens in the vent terminal
and combustion air terminal (when used).
3. Keep the appliance area clear and free from
combustible materials, gasoline, and other
flammable vapors and liquids.
4. If the appliance is not going to be used for
extended periods in locations where freezing
normally occurs, it should be isolated from the
system and completely drained of all water. All
systems connected to it should also be drained or
protected from freezing.
5. Low water cutoffs, if installed, should be checked
every 6 months. Float type low water cutoff
should be flushed periodically.
6. Inspect flue passages, and clean with brushes/
vacuums, if necessary. Sooting in flue passages
indicates improper combustion. Determine the
cause and correct.
7. Inspect the vent system and air intake system, and
ensure that all joints are sealed properly. If joints
need to be resealed, completely remove existing
sealing material, and clean with alcohol. Apply
new sealing material, and re-assemble.
7.2 Appliance Maintenance and
Component Description
Only genuine Laars replacement parts should be used.
Caution
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation. Verify proper operation after
servicing.
See Figure13 for location of gas train and control
components.