COMBAT® CTU UNIT HEATERS INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 13: SERVICING 13.1 Servicing Instructions
After commissioning, the heater will require maintenance to be carried out annually. If the heater 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
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 24, Section 11 through Page 27, 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 32, Section 15 through Page 34, Section 15.4.
NOTE 2: Check all gas pipes and pipe joints to ensure there are no cracks or gas leaks. Any cracks in the pipes or pipe joints must be repaired.
NOTE 3: Inspect all suspended components and hardware. Insure that they are in good condition, properly tightened, and corrosion free.
13.2 Burner Maintenance
1.Open the hinged door and remove the burner compartment cover. See Page 36, 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 36, 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(s) and use a small brush or duster to clean the fan blades from each side. Replace fan(s) when done.
13.3.1For CTUB & CTUC Centrifugal Fan Models
CTUB and CTUC models are fitted with thermally protected three speed fans. The number of fans can be found on Page 41, Section 16.9 and the standard air flow for each model can be found on Page 7, Section 4.3.
For CTUC models, the fans may be accessed via the removable panels in the top, bottom and sides of the inlet spigot compartment as required.
Do not operate at higher speeds than the original setting on the heater without prior consultation with
The "HIGH" speed option is available to give the normal required air flow against higher static pressures and is not intended to be operated free blowing or against low resistance. Use of the fans under these conditions may cause the fan thermal overload to operate and the fan thermostat to cycle. All fans on a heater must be set to operate at the same speed. For Models 50 - 115, they will be switched using a fan relay built into the heater. See Page 40, Section 16.8.2.
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.
13.5 Gas Control Valve Maintenance
No regular maintenance is required on these devices. To change gas control valves, See Page 35, Step 16.1 and Page 39, Section 16.5.
Do not repair or disassemble on site. Replace faulty gas valves with genuine ROBERTS GORDON® replacement parts.
13.6 Flue Fan
The flue fan should not require maintenance. However, if the air pressure switch is causing burner lockout, then remove the flue fan from the vent box by unscrewing the screw at the outlet flange and the flue fan mounting plate (See Page 38, Section 16.4). Ensure that the fan is free to run and that the fan wheel is clean.
30
