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Noritz · Tankless water heater

06 Low recirculation flow (warning only)

Low severity Noritz NRCR

What the control is telling you

NRCR only. Warning that recirculation flow is low; the owner's guide groups 06, 061 and 062 as recirculation abnormality.

Applies to: Noritz NRCR92 / NRCR111

Likely causes

  • Clogged return line filter
  • Air in the hot/return line (dedicated mode)
  • Clogged crossover valve filter or valve installed the wrong way (crossover mode)

Test and repair steps

  1. Clean the return line filter.
  2. Dedicated mode purge air from the domestic hot and return lines.
  3. Crossover mode clean the crossover valve filter and check valve orientation.
  4. Check MM17 recirculation flow rate and MM86 recirculation mode.
  5. Contact Noritz if the warning keeps returning.

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Source: Noritz NRCR Pro training (NRCR92/NRCR111, Printable V3), NRCR Pro specific error codes, p.29; Noritz EZ/NRCR Owner's Guide (Rev. 10-25), Checking for error conditions, p.31. 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.