On both Gas Furnace and Gas Boiler Precision Tune up:
Adjust thermostat settings and level
(Recommend battery replacement annually)
Inspect basement exhaust flues for safety
Measure adequate air for safe combustion of appliances
Inspect heat exchanger / boiler block for deterioration
Brush, clean and adjust burners
Clean and adjust ignition or pilot assembly
Clean flame sensor / Inspect thermocouple condition
Ohm check of hot surface ignitor
Check wiring and connections
Measure voltage and Amp draw
Vacuum burner compartment
Check gas manifold pressure
Clear condensate drain assembly and line
Check draft and Chimney
Test operating efficiency
Test for carbon monoxide presence in exhaust
Check gas fittings near furnace/boiler for leaks
Reseal exterior venting penetration if needed
Inform customer of AMA savings for next year

On Gas Furnaces only:
Brush and vacuum furnace and heat exchanger
Clean blower assembly and louvers
Check motor bearings (lubricate if necessary)
Adjust for proper temperature rise
Remove and clean filter or recommend replacement
Test furnace high limit safety shut off
Test for carbon monoxide presence in air system

On Gas Boilers only:
Brush and vacuum boiler and block
Check expansion tank for proper operation
Record system pressure reading at limit
Check pressure reducing valve and backflow preventer
Check pressure relief valve for leaks
Check air elimination systems
Check and oil system circulator pump(s)
Test aquastat and record settings
Check zones for proper operation
System water PH level