Servicing 13.1 Servicing Instructions

DUALAIR® HEATING AND COOLING UNITS INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 13: SERVICING 13.1 Servicing Instructions

After commissioning, the DualAir® unit will require maintenance to be carried out annually. If the DualAir® unit is used in a dirty or dusty area, more frequent maintenance may be necessary.

Installation, service and annual inspection of heater must be done by a contractor qualified in the installation and service of gas-fired heating equipment.

WARNING

Cut Hazard

Turn off gas and electrical supply before maintenance. Fan can start automatically at any time.

Failure to follow these instructions can result in severe injury or product damage.

NOTE 1: After any maintenance or repair work always test fire the heater in accordance with the commissioning instructions on Page 21, Section 11

through Page 24, Section 11.9 to ensure all safety

systems are in working order before leaving the heater to operate. Minor faults may be traced by using the troubleshooting charts on Page 31,

Section 15 through Page 34, Section 15.5.

NOTE 2: Check all gas pipes and pipe joints to ensure there are no cracks or gas leaks.

NOTE 3: Inspect all suspended components and hardware. Insure that they are in good condition, properly tightened, and corrosion free.

13.1.1 Cooling Equipment

The cooling coil does not require maintenance except that during filter replacement it is recommended to clean the surface of the coil with a soft brush and vacuum cleaner. Carry out any maintenance recommended by the condenser manufacturer.

13.1.2 Filters

The air filters should be inspected regularly to ensure that no excessive build up of deposit is being experienced. If heavy deposit is being formed, then the filters may be cleaned using a vacuum cleaner. Filters should be replaced at least every four months

to ensure that adequate air flow.

The cooling equipment will automatically turn off should the air flow drop to a preset low value even though the fan will still run. The maximum resistance across a dirty filter should be no more than 150 Pa (1.5 mbar) and the dirty filter warning light will be on. A resistance higher than this indicates that the filters must be replaced.

13.2 Burner Maintenance

1.Open the hinged door and remove the burner compartment cover. See Page 37, Section 16.2.

2.Clean any deposits from the main burner which may have formed in the injectors or venturi of the burner. See Page 37, Section 16.2.

3.Remove the ignition electrode and flame probe. Check condition of ignition electrode and flame probe. Clean off any deposits which may have been formed, check condition of ceramic insulators. Replace as necessary.

13.3 Fan/Motor Assembly Maintenance

The main fan bearings are permanently sealed and do not need lubrication. Before cleaning, turn off gas and electrical supply. Remove the fan compartment covers and use a small brush or duster to clean the fan blades from each side. Replace fan(s) when done.

Figure 16: Belt Tension

8 mm to 10 mm

Fan

MotorPulley

Pulley

Check the condition and tension of the drive belts. The condition is best inspected with the belts removed. Check for chaffing or lateral cracks. Replace belts as a matched pair as necessary.

Do not over-tighten belts, as this may cause bearing damage.

13.4 Heat Exchanger Maintenance

The heat exchanger will remain clean unless a problem has developed with combustion. Inspect the heat exchanger. Look for signs of overheating at the front tubes which may indicate burner over firing or persistently low air flows.