Boilers (Oil and Propane) 

• Aquastat
• Automatic air vent
• Backflow valve
• Circulator (up to 1/8th HP)
• Expansion tank-#60 or below
• Flo checks
• Low water cutoff (for non-steam systems)
• Mixing valve
• Water feeder (standard, non-steam system)
• Zone valves and power heads
• Relief valves (boiler and domestic)

Steam Boilers (only)

• Pressuretrol 

Burners

• Blast tube
• Burner fan
• Burner motor (up to ¼ HP)
• Burner tube
• Burner parts only (entire burner not covered)
• Couplings
• Delayed action valve
• Electrode wiring and clips
• Electrodes
• End cone
• Ignitor
• Ignitor wiring and clips
• Primary control 

Oil Burners (only)

• Burner firomatic
• Cad cell kit
• Fuel pumps and gasket
• Nozzle and nozzle adaptor
• Oil filter cartridge
• Porcelains

Propane Burner (only)

• Flame sensor
• Gas valve
• Ignition module
• Pilot assembly
• Thermocouple/thermopile

Warm Air Furnace

• Blower belt and pulley
• Blower motor
• Blower shaft and bearings

Propane Boiler or Furnace

• Combustion fan
• Combustion motor

Heating Appliances (boiler, furnace, water heaters, and space heaters)

• Draft regulator
• Single wall galvanized or PVC vent pipe
• Smoke pipe
• Pressure switch

Heating Appliance Control

• Limit controls
• PC boards (required for standard operation)
• Thermostat (non-WIFI)
• Transformer (24-volt)
• Transformers
• Relay
• Stack relay
• Emergency switches

Fuel Delivery Piping

• Fill and vent piping
• Oil supply lines
• Propane piping
• Line pressure regulators
• Oil tanks
• Gauges
• Whistles/alarms
• Frozen oil lines

Heating Distribution System Components

• Duct work
• Registers and grilles
• Heat piping from boiler to baseboard/radiator
• Zone dampers for warm air systems
• Electronic air filters

Steam Systems

• Piping
• Vents
• Low water cutoffs and water feeders

Heating Elements

• Baseboard
• Radiators
• Kick space heaters
• Panel radiators
• Hanging heaters (Modine)
• Roof top units
• Combination units
  • Wood/oil
  • Wood/propane
• Radiant systems
  • In floor
  • Staple up
• Controls for radiant systems

Antifreeze Condensate Systems

• Steam systems 
  • Piping
  • Pumps
  • Tanks
  • Traps
• Condensing boilers and furnaces
  • Pumps
  • Piping/tubing

Venting Systems

• Chimneys
• Power venters
• Direct vent piping
  • Vent and fresh air intake
  • Terminations
• Polypropylene venting
• Draft inducers

Domestic Hot Water Systems

• Tankless coils
• Recirculation circulators and piping
• Domestic thermal expansion tanks
• Domestic circulators (bronze/stainless steel)
• Domestic plate heat exchangers

Electrical Distribution Wiring

• Electrical panels
• Boxes
• Wiring (other than on heating appliance)
  • Including thermostat wiring to - from thermostat to controls

Add On Controls

• Outdoor reset controls
• Wi-Fi thermostats and support devices

Any Unit Larger Than

• Oil 2.0 Gallons per hour
• Propane 200,000 BTU per hour