Describe the symptom
Record when the change started and at which load it occurs. Distinguish a missed outlet temperature from a changed flow rate or increased consumption.
Compare operation with design
Measure temperatures, flow rates and pressure differences at the same operating point. Reduced performance alone does not prove fouling; system conditions may have changed.
Prepare a service record
Collect before/after readings, units, measurement confidence, maintenance dates and plant modifications. The aim is a sound technical investigation, not a remote diagnosis.
Prepare for the discussion
- Fluids, composition and relevant material requirements
- Flow rates and inlet/outlet temperatures on both circuits
- Design conditions and allowable pressure drop on each side
- Exact model, nameplate and current technical documents