T2DA : Low Temperature A

  • Use a smaller mix chamber that is rated for the unit in use.  If recirculating, decrease flow or decrease temperature setpoint.

 

  • Swap A and B heater output cables and RTD cables and see if issue follows.  If so, replace RTD.

 

  • Confirm resistance of heater.  Heater resistance should be 18-21 Ω for each heater element, 9-12 Ω combined for 10 kW systems, 6-8 Ω for 15 kW systems, and 4-6 Ω for 20 kW systems.  If out of tolerance, replace heater element.
  • Check for loose heater element wires or loose green connector at TCM.