This chapter is divided into two sections:
• Maintenance procedures
• Troubleshooting guide
Preventive maintenance is the key to a reliable, safe and
efficient system. The core of any preventive maintenance
system is a list of periodic tasks. The following are
suggestions for a monthly list and a yearly list.
NOTE: The monthly list and yearly lists are an average
interval. If your environment is dirty, the intervals may be
1. Inspect flame-sensing devices for good condition and
2. Check for proper inlet air/gas ratios.
3. Test all the alarm systems for proper signals.
4. Check ignition spark plugs and check proper gap.
5. Check valve motors and control valves for free, smooth
action and adjustment.
6. Check for proper operation of the ventilating
7. Test the interlock sequence of all safety equipment;
manually make each interlock fail, noting that related
equipment closes or stops as specified by the
8. Test flame monitoring control system by manually
shutting off gas to burner.
9. Test main fuel hand-valves for operation.
10.Clean or replace the combustion air blower filter.
1. Test (leak test) safety shut-off valves for tightness of
2. Test air pressure switch settings by checking switch
movements against pressure settings and comparing
with actual impulse pressure.
3. Visually check ignition cable and connectors.
4. Inspect impulse piping for leaks.
5. Clean and inspect all the burners.
6. Remove and clean the orifice plates .
7. Make sure that the following components are not
damaged or distorted:
• burner nozzle
• spark plugs
• flame sensors
• flame tube or combustion block