A Building Management System only saves energy and keeps occupants comfortable if it is looked after. Yet many BMS “services” amount to a quick look at the front end and a signature on a job sheet. This checklist sets out what a proper BMS maintenance visit should cover, so facilities managers in London and the South East know what to expect — and what to ask for.
New to the subject? Start with our guide to mechanical, electrical and BMS services. If your system is old or closed, see our guide to Niagara 4 BMS upgrades.
1. Supervisor and front end
- Check the supervisor (for example Niagara 4) is running, licensed and has adequate disk space and memory
- Confirm all controllers and integrated devices are online — investigate any that are offline or in fault
- Review user accounts and passwords; remove leavers and default credentials
- Check graphics are accurate and every point shows a live, sensible value
2. Controllers and panels
- Visually inspect control panels for overheating, loose terminations, moisture and dust
- Check panel power supplies, fuses and 24V transformers
- Verify controller clocks are synchronised so schedules run at the right time
- Check network health — BACnet and Modbus communication errors, duplicate addresses, slow polling
3. Sensors and field devices
- Spot-check temperature, humidity, pressure and CO₂ sensors against a calibrated reference instrument
- Test 4–20 mA and 0–10V signals at the controller to confirm transmitters are reading correctly
- Stroke valve and damper actuators fully open and closed and confirm feedback
- Check variable speed drives respond to BMS commands and report status and faults
Bad sensor data is one of the biggest hidden causes of wasted energy: if the BMS thinks a room is cold when it isn’t, it will keep heating it.
4. Alarms
- Review the alarm history for repeat and nuisance alarms
- Fix the root cause or adjust limits and delays so only meaningful alarms remain
- Test that critical alarms (plant failure, high temperature in comms rooms, leak detection) actually reach the right people by email or SMS
5. Schedules, setpoints and overrides
- Compare time schedules with actual building occupancy
- Load bank holidays and closure periods into holiday calendars
- Find and release any manual overrides left in hand — plant forced on is a common source of waste
- Check heating and cooling setpoints and deadbands are sensible and consistent
6. Trends and energy performance
- Review trend logs for hunting control loops, plant short-cycling and simultaneous heating and cooling
- Check energy meters are reading and logging
- Flag optimisation opportunities, such as fan coil unit energy savings
7. Backups and documentation
- Take a full backup of the supervisor and controller databases and store it off site
- Update points lists, schematics and the description of operation after any change
- Leave a written service report with findings, actions taken and recommendations
How often should a BMS be serviced?
For most commercial buildings, at least one full service a year is the minimum, with quarterly or six-monthly visits for larger, busier or critical sites such as data rooms and healthcare. Sensor calibration checks and backups should be part of every visit.
BMS maintenance in London and the South East
Parsek Group provides BMS servicing, fault finding and controls upgrades for facilities management companies and building owners across London and the South East. Our engineers are Niagara 4 TCP and Distech EC-series certified, and work with BACnet/IP and Modbus systems every day.
Want your BMS checked properly? Contact Parsek Group to arrange a service visit.