Don’t Let Maintenance Slide on Your Commercial Boiler
Commercial boilers are sturdy pieces of equipment that are designed for long life with minimal attention. However, your boiler still requires regular inspections and maintenance to run properly and safely. Generally, an annual maintenance visit by a qualified professional is sufficient, though some modern high-efficiency models may need adjusting twice a year to keep them working at their peak. Local, state and national boiler codes may also require inspection and maintenance at specified intervals. Following is a brief explanation of what you can expect your HVAC professional to do during a boiler maintenance session.
Establish or revise a maintenance plan: A maintenance plan includes schedule of maintenance dates and a list of specific tasks that should be done. It should also include an up-to-date set of records detailing when maintenance and repairs were conducted and what actions were taken. If there is no existing plan, your HVAC expert can help you establish one. Make sure the technician updates the records with detailed information on what was done to the boiler.
Remove and inspect the burner: The burner is the component that provides the flames that produce heat, so make sure it is working correctly. By removing the burner, the technician also provides easy access to the combustion chamber for additional checks.
Inspect flue passages: Look for soot or moisture in the flue passages. Soot indicates problems such as insufficient combustion air or a fuel mixture that is too rich. Moisture indicates the system is running at a temperature that’s too low.
Check vent pipes: Ensure vent pipes are clear for proper air flow and venting of combustion gases. Look for any white, powder-like residue. This indicates condensation in the pipe. This acidic residue can cause severe damage to pipes. Ensure the technician adjusts stack temperatures to prevent condensation.
Inspect flame-sensing rods: Ensure proper gaps in the flame-sensing or spark rods and make sure the ceramic structure holding these rods is free from cracks or damage.
Ensure proper fan and blower function: Make certain fans and blowers that distribute heated air are clean and functioning. Clean the fans and, if needed, lubricate them to make sure they’re turning properly.
Check filters: If the system contains any filters, make sure they are clean and, if not, change or clean them.
Test safety controls and interlocks: Make sure all safety controls and devices, such as the pressure-relief valve, low-water cutoff controls, high and low gas-pressure safety controls, and burner safeguards are functioning properly.
Check valves and switches: Make sure the block valves are working correctly. Make sure all combustion air proving switches will open by removing air lines. Test and adjust the purge timer to ensure it’s still at the proper factory setting.
Test flue gases: Engage the boiler until it reaches operating temperatures, then test the system’s flue gases to make sure they’re being properly vented and that they are at the correct temperature.
Analyze flue gas composition: Test flue gases to ensure proper concentrations of oxygen, carbon monoxide and carbon dioxide. In most cases, the gases should consist of 8-10 percent carbon dioxide and contain less than 20 parts per million of carbon monoxide. Make sure the combustion chamber is properly sealed to avoid combustion gas leaks.
Adjust fuel and oxygen mix: Adjust the modulating fuel valve to ensure proper mixture of fuel and oxygen. This ensures that the boiler will run cleanly and efficiently.
Check operator and high temperature limit: When the boiler is at operating temperatures, check the operator and high temperature limit controls to ensure they will shut off the burner to reduce internal temperatures if needed.
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