LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 58)

Page 54 LAARS Heating Systems
Section 10
MAINTENANCE
WARNING
Disconnect all power to the appliance before
attempting any service. Contact with electricity can
result in severe injury or death.
10.1 System Maintenance
Do this once a year, unless otherwise noted.
1. Lubricate the system water-circulating pump, if
required, per the instructions on the pump.
2. If a strainer is employed in a pressure reducing valve or
the piping, clean it every six months.
3. Inspect the venting system for obstruction or leakage at
least once a year. Periodically clean the screens in the
vent terminal and combustion air terminal (when used).
4. Keep the area around the appliance clear and free of
combustible materials, gasoline, and other flammable
vapors and liquids.
5. 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.
6. Low water cutoffs, if installed, should be checked every
year. Float-type low water cutoffs should be flushed
periodically.
7. Inspect and clean the condensate collection, float switch
and disposal system yearly.
8. When a means is provided to neutralize the condensate,
ensure that the condensate is being neutralized properly.
9. Inspect the flue passages, and clean with a brush or
vacuum if necessary. Sooting in flue passages indicates
improper combustion. Determine the cause for this and
correct it.
10. Inspect the vent system and air intake system, and
ensure that all joints are sealed properly. If any joints
need to be resealed, completely remove any existing
sealing material, and clean the joint(s) with alcohol.
Apply new sealing material, and reassemble.
10.2 Appliance Maintenance and
Component Description
Use only genuine LAARS replacement parts.
Caution
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and danger-
ous operation. Verify proper operation after servicing.
The gas and electric controls in the unit are engineered
for long life and dependable operation, but the safety of
equipment depends on their proper functioning. Only a
qualified service technician should inspect the basic items
listed below every year:
a. Appliance control f. Flow switch
b. Automatic gas valve g. Low water cutoff
c. Pressure switches h. Burner
d. Blower i. Heat exchanger
e. Pump
Burner
Check the burner for debris. Remove the blower arm assembly
to access the burner. Remove the four bolts connecting the
blower to the arm. (See Figure 47.) Remove the five bolts
which hold the burner arm in place. Pull the burner up and
out. Clean the burner, if necessary, by blowing compressed
air from the outside of the burner into the center, and wipe
the inside clean with glass cleaner. A dirty burner may be an
indication of improper combustion or dirty combustion air.
Determine the cause of this, and correct it. If the burner gasket
is damaged, replace it when replacing the burner.
NOTE: When installing the burner, make sure the flange
is aligned with the mating surface, as each is keyed to
control the fit.
Modulating Gas Valve / Venturi
The modulating gas valve consists of a valve body that
incorporates the On/Off gas flow control and a negative
pressure regulator. It provides the air/gas ratio control in
combination with the Venturi to the unit. It is designed to
operate with a gas supply pressure between 4 and 13 inches
w.c. To remove the gas valve and/or Venturi, shut off the 120
Volt power supply to the boiler. Turn off all manual gas valves
connecting the boiler to the main gas supply line. Remove
the front door of the boiler to gain access to the gas valve
and Venturi. Disconnect the four flange bolts connecting the
gas manifold pipe to the gas valve. Remove the electrical
connections to the gas valve. Remove the bolts connecting the
Venturi flange to the blower. This allows the entire gas valve
and Venturi assembly to be removed to facilitate inspection
and cleaning.
Reassemble the valve/Venturi assembly in reverse order,
making sure to include all gaskets and O-rings. Turn on
the manual gas valves and check for gas leaks. Turn on the
120 Volt power. Place the unit in operation following the
instructions in Section 9. Once the boiler is operating. check
for leaks again and confirm that all fasteners are tight.
Check the appliance setup according to Section 9.
Appliance Control
The NeoTherm unit has an integrated control that incorporates
manual reset high limit control, operating temperature
control, modulating control, ignition control, outdoor reset
control, pump control and many other features. If any of
these features are thought to be defective, please consult the
factory for proper trouble shooting practices prior to replacing