Boiler Maintenance Checklist

Following a regular maintenance schedule for your building’s boiler plant will go a long way toward minimizing breakdowns and service interruptions. (In New York City, most low-pressure and high-pressure boilers must be inspected annually and a report filed by December 31 of each year.) Here are some key items that should be a part of any building’s operational plans.

A Boiler Diagram
A Scotch-marine steam boiler, common in residential buildings, typically lasts 25 to 30 years with proper maintenance.
Annual Maintenance

These maintenance items should be done once a year by a heating contractor between heating seasons (June to September):

  • Inspect and clean fireside surfaces.
  • Inspect all burner refractory material.
  • Inspect all manhole gaskets for leaks.
  • Inspect and test all system valves.
  • Inspect and test all safety valves.
  • Clean and rebuild low water cut-off.
  • Recalibrate all operating controls.
  • Overhaul feed water pumps.
  • Clean condensate receiver.
  • Inspect electrical terminals.
  • Switch boiler automation to summer mode.
  • Check fuel oil levels.
  • Clean and inspect chimneys.
  • Clean and tune boiler and components. 
Periodic Maintenance

These items should be addressed by the building’s maintenance staff on a continual basis, or as often as indicated below:

  • Check and maintain proper oil level in compressor lube tank (daily). Use SAE 20/30 oil.
  • Clean oil filters at least twice a week:
    – Shut-off power to pump motor.
    – Close shut-off valve.
    – Pull out filter. Clean filter and re-insert into housing.
    – Place strainer cap into proper position, restart pump motor, and check vacuum.
    – Vacuum reading must be high; if not, check seal on cap. If reading is high, then open oil valve.
    – Check oil pressure reading at the burners.
  • Keep sight glasses clean. This allows for a clear view of the burner flame and any carbon build-up on the boiler’s combustion chamber (as needed).
  • Keep air filters clean. A clogged air filter can lead to poor air/oil mixture and carbon build-up (as needed).
  • Check oil circulation temperature at sidearm pre-heaters. Inlet temperature should be 110° F to 120° F, and outlet temperature should be 140° F to 150° F for No. 6 oil (daily).
  • Flush drain low water cut-offs/sidearm oil pre-heater (twice a week).
  • Flush drain low water cut-offs while burner is on and a flame is present in the boiler’s combustion chamber. When the unit is flushed, the flame should turn off. Allow the burner to start before checking other low water cut-offs.
  • Flush down water-line heater, shut off lower isolation valve, open drain valve to flush unit, shut drain off valve, and reopen isolation valve. 
  • Conduct boiler bottom blowdown to clear sludge and sediment, control high water, and control chemical treatment concentrations (monthly or as needed).
  • Monitor the make-up water being added to the boiler and/or the boiler feed unit. Since the system operates via closed loop, an excess amount of fresh (untreated, oxygenated) water supply is detrimental to boiler components and is often a sign of a leak in the system. 
  • Monitor smoke alarm on a weekly basis:
    – Wipe light source and receiver.
    – Smoke alarm unit should not be set at its highest point.
    – Unit should be set in accordance with NYC Buildings Department standards.
  • Maintain a rigorous boiler chemical feedwater treatment program. 
  • Maintain a boiler room log to record any problems and routine maintenance.
  • Check combustion, inspect burner controls, and inspect burner operation.
  • Conduct trap inspection program with replacement of trap elements in apartment units and steam traps within the cellar.
  • Conduct pipe inspection program to ensure all pipes are pitched in the direction of steam source (one-pipe steam systems) or condensate drainage (two-pipe systems).