10 - maintenance, 1 system maintenance, 2 appliance maintenance andcomponent description – LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual User Manual

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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

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