E02 error appears and the heater will not start or shuts off shortly after starting.

Safety first: Disconnect power before removing filters or hoses. Do not run the heater without proper water flow.

• Check water level: Ensure the water level is between the MIN and MAX lines on the spa wall. Low water can cause poor flow and trigger E02.
• Clean or replace filter: Remove the filter cartridge from the filter housing. Rinse thoroughly with a garden hose from the inside out. If the filter is discolored, collapsed, or older than 2–4 weeks of use, replace it with a new SaluSpa-compatible filter cartridge.
• Inspect inlet/outlet fittings: Check the spa liner’s inlet and outlet ports for debris, leaves, or scale buildup. Clear any obstructions.
• Bleed air from system: With power off, slightly loosen the air bleed valve (if equipped) on the pump/heater unit until water seeps out, then retighten. This helps remove trapped air that can reduce flow.
• Restart circulation: Plug the spa back in, start the filter/circulation mode only (no heat) and verify strong water movement at the return jet. If flow is weak and E02 returns, the internal circulation pump may be failing.

Warning: Do not bypass flow sensors or run the heater with blocked flow; this can overheat the heater housing and cause permanent damage.