01Complete pre-start checks
- Confirm the system is filled with the specified heat-transfer fluid and the expansion tank level is correct
- Check valve lineup, vents, drains, strainers, expansion path and leak-tightness
- Verify pump rotation, coupling, lubrication and expected flow direction
- Confirm temperature, pressure, level and flow instruments are installed and calibrated
- Function-test low-flow, low-level, over-temperature and emergency shutdown circuits
Use the approved commissioning checklist for the specific heater and plant. This overview is not a substitute for the manufacturer’s operating instructions, the site procedure or the fluid supplier’s guidance.
02Establish circulation before heat
Start the circulation pump with heater power isolated. Confirm stable flow, acceptable pump condition, no abnormal noise and no leakage. Remove trapped air using the system’s designed venting points and verify that the expansion tank and return path behave as expected.
Do not energize the heater until the required flow permissive is proven and the system is configured to remove heat safely. The minimum circulation requirement depends on the heater design and fluid properties.
03Raise temperature in controlled steps
Follow the fluid and equipment supplier’s ramp rate and temperature hold points. During commissioning, monitor inlet and outlet temperature, pressure, flow, pump condition and expansion-tank behavior. Water contamination can flash to vapor as temperature rises, so unexpected pressure oscillation, pump cavitation, knocking, foaming or unstable flow requires stopping the heat-up and following the site response procedure.
Avoid relying on a universal hold temperature or ramp rate. The correct sequence depends on the fluid, system volume, venting arrangement, pressure design and equipment manufacturer. Do not open hot or pressurized equipment to accelerate dewatering.
04Document acceptance and operating limits
Record the fluid batch and fill volume, instrument readings, interlock test results, leak checks, ramp profile and any abnormalities. Confirm the final operating setpoints and alarm/trip actions with the process and equipment teams before handing over the system.
If moisture cannot be removed as expected, circulation becomes unstable, or the fluid shows signs of degradation, stop and investigate with the supplier. Continuing to increase temperature can worsen the hazard or damage the heater.
↗Related guide
Related guide: Expansion Tanks in Thermal Fluid Systems: Role, Flow Path and Sizing Basis