Building automation systems are often neglected until something breaks. But like any technology infrastructure, BMS systems benefit from proactive maintenance. Regular attention extends system life, reduces emergency calls, and keeps your building running efficiently.
Why BMS Maintenance Matters
Unlike mechanical equipment, BMS systems don't make noise or show visible wear when they're struggling:
- Sensors drift out of calibration
- Controller memory fills with old trends and logs
- Network connections become intermittent
- Software vulnerabilities accumulate
- Backup batteries deplete
By the time you notice a problem, it may have been wasting energy or causing comfort issues for months.
Recommended Maintenance Schedule
- ☐ Review system alarms and resolve issues
- ☐ Check key sensor readings against known conditions
- ☐ Verify schedules are current and appropriate
- ☐ Confirm remote access is working
- ☐ Review energy trends for anomalies
- ☐ Calibration check on critical sensors
- ☐ Test critical alarms (freeze protection, limits)
- ☐ Verify backup batteries in controllers
- ☐ Clear accumulated log files
- ☐ Check network communication quality
- ☐ Update documentation for changes
- ☐ Full sensor calibration survey
- ☐ Test all critical override and safety functions
- ☐ Review and optimize control sequences
- ☐ Check firmware versions and plan updates
- ☐ Backup all programming and configurations
- ☐ Test backup restoration procedure
- ☐ Comprehensive system audit
- ☐ Replace backup batteries proactively
- ☐ Apply software/firmware updates
- ☐ Review user accounts and permissions
- ☐ Assess system for upgrade planning
- ☐ Review maintenance contract and history
Sensor Calibration
Sensors are the eyes and ears of your BMS. Calibration drift is normal but must be corrected.
Temperature Sensors
Compare to calibrated reference thermometer. ±1°F acceptable for space sensors, ±0.5°F for critical applications.
Pressure Sensors
Zero check at atmospheric pressure, compare to calibrated gauge, check for physical damage or clogged ports.
Humidity Sensors
More prone to drift than temperature sensors. Consider replacement rather than calibration if sensors are old.
Software and Firmware Maintenance
- Archive old trend data to prevent database bloat
- Clear unnecessary logs
- Compact databases if supported by platform
- Monitor storage capacity
Backups
Automatic daily backups: Configure for unattended operation
Manual backup before changes: Always backup before modifications
Test restoration annually: Verify backups actually work
Store offsite or cloud: Protect against local disasters
Network Maintenance
Communication Quality
- Monitor communication errors and retries
- Check response times for remote devices
- Investigate intermittent communication problems
Physical Infrastructure
- Inspect cable connections
- Check for damaged or deteriorating cables
- Verify termination resistors on MS/TP networks
- Ensure proper grounding
Documentation Maintenance
Documentation is often the first casualty of change. Make documentation maintenance part of your routine:
- Update point databases when changes are made
- Maintain current as-built drawings
- Document sequences of operation
- Keep equipment integration documentation current
- Record maintenance history
Service Contract Considerations
"A good maintenance contract should include scheduled preventive maintenance visits, remote monitoring and support, priority response for emergency calls, software updates and patches, and clear scope of covered vs. additional services."
Building In-House Capability
Even with a service contract, some maintenance capability in-house helps:
- Staff trained to use the BMS interface
- Ability to recognize and report problems
- Basic troubleshooting skills
- Understanding of building-specific sequences
Getting Started
At Controls NYC, we offer comprehensive BMS maintenance services, from routine preventive maintenance to full-service contracts. We also train building staff to maximize in-house capability.
Contact us to discuss a maintenance program for your building.
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Whether you're evaluating an upgrade, dealing with a failing system, or just want a second opinion — we're happy to talk through your options.
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