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Rinnai · Combi boiler

250 Condensate pump switch tripped (accessory)

High severity I-Series Plus 150K and smallerI-Series Plus 175K and higher

What the control is telling you

Applies when an external condensate pump's float switch is wired into the unit; condensate has backed up and tripped the switch, often because the pump stopped working.

Applies to: I-Series Plus boilers — 150K BTU and smaller and 175K BTU and higher (Combi and Solo)

Likely causes

  • No power to condensate pump
  • Pump failed or reservoir full
  • Clogged or frozen drain line
  • Loose, damaged or broken wiring
  • No air gap in drain line
  • Safety switch is not normally open (N.O.)

Test and repair steps

  1. Confirm the condensate pump has power.
  2. Check that the condensate reservoir is empty.
  3. Confirm the third-party pump actually runs.
  4. Make sure the drain line isn't clogged or frozen and includes an air gap.
  5. Inspect all wiring for loose, damaged or broken connections.
  6. Confirm the pump safety switch is a normally open (N.O.) type.

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Source: Rinnai Troubleshooting I-Series Plus Boiler Diagnostic Codes (800000375), p.14. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.