Plate heat exchangers rarely fail without warning. Most give plenty of signals first — the trick is noticing them before a small problem turns into a shutdown. These are the signs we see most often.
1. Pressure drop is creeping up
Fouling narrows the flow channels between plates, so the same flow needs more pressure to push through. If you log pressure either side of the unit, a steady rise over weeks or months is one of the earliest and most reliable warnings.
2. Outlet temperatures are drifting
A layer of scale or sludge insulates the plate. The unit still runs, but it transfers less heat, so the hot side leaves warmer and the cold side leaves cooler than design. Operators often compensate by increasing flow, which hides the problem for a while.
3. Gaskets are weeping at the edges
Small drips or crystallised deposits around the edge of the plate pack usually mean gaskets are hardening or losing their seal. Weeping rarely stops on its own, and repeatedly tightening the pack to chase it can damage plates.
4. Tightening no longer stops a leak
If the pack is already at its specified dimension and still leaks, the gaskets have taken a permanent set or a plate is damaged. Further tightening risks deforming plates.
5. Signs of cross-contamination
Product or fluid appearing where it shouldn’t — a change in water quality, unexpected loss of one medium, or contamination found in testing — can point to a cracked or pinholed plate. This needs attention quickly.
6. Energy or pumping costs have risen
When a unit transfers less heat, the rest of the system works harder to make up the difference. Higher pump, boiler or chiller energy without a change in load is worth investigating.
7. There’s no service record
If nobody can say when the unit was last opened, inspected or re-gasketed, it is due for an inspection. A baseline inspection gives you a starting point for future maintenance.
What to do next
Start by recording the nameplate details, current pressures and temperatures, and taking photos of the unit. That information makes it much easier to decide whether an on-site inspection, a clean, or a workshop service is the right next step. See our servicing options.
Seeing one or more of these signs? Request a quote or call (02) 9897 7371.