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FlowMax · Combi boiler

E06 Domestic hot water (DHW) sensor fault

Medium severity FlowMax condensing combi (FLOWMAX-90/120)

What the control is telling you

The DHW sensor reads out of range. The 120 troubleshooting table does not list E06; checks below follow the same sensor procedure the manual gives for E05/E12.

Applies to: FLOWMAX-90, FLOWMAX-120

Likely causes

  • DHW sensor faulty
  • DHW sensor wire disconnected or wet

Test and repair steps

  1. Turn off power before working on sensor wiring.
  2. Check the DHW sensor connector and wiring for looseness, damage or moisture.
  3. Unplug and measure the sensor; the manual's other sensors are 10 kOhm at 25°C (77°F) - confirm the DHW sensor spec against the parts list.
  4. Replace the sensor if it reads open or shorted.
  5. Restart and confirm the code clears.

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Source: FlowMax FLOWMAX-120 Instruction Manual, 6.11 Diagnostics error code list, p.67; FlowMax FLOWMAX-90 User Manual, Diagnostics - Error codes, p.8-9. 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.