E-203: Chilled water flow loss

Q: How do I check a E-203 fault?

1. Confirm pump running 2. Walk the chilled-water valve line-up 3. Check strainer dP 4. Test flow switch Safety: Refrigerant work requires certified technicians; isolate power before panel access.

Probable causes

Pump trip
Closed valve
Clogged strainer
Faulty flow switch

Step-by-step checks

Confirm pump running
Walk the chilled-water valve line-up
Check strainer dP
Test flow switch

Safety: Refrigerant work requires certified technicians; isolate power before panel access.

Sample code — verify with the OEM manual for your exact model.

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Frequently asked questions

What does E-203 mean on a Chiller?

E-203 usually indicates: Chilled water flow loss. Confirm the meaning in the manufacturer's manual for your model.

What causes E-203?

Pump trip; Closed valve; Clogged strainer; Faulty flow switch.

How do I check a E-203 fault?

Work through the numbered checks above in order, recording readings as you go. Refrigerant work requires certified technicians; isolate power before panel access.

Other Chiller codes

Disclaimer: Fault code information is guidance only. Codes and meanings vary between manufacturers and models — always follow the manufacturer's manual and your site's safety procedures, and use qualified personnel for electrical, pressure, refrigerant and combustion work.