The furnace reports a twinning-configuration fault affecting a paired-furnace setup.
Professional Required
Twinning feature error (TWIN error)
Twinning feature not working; furnace fails to operate; LED displays EEH
Improper twinning wiring connection or control board fault
A technician familiar with twinned furnace installations should check the specified interconnecting wiring and control configuration.
Twinning wiring, integrated control board
Contact a qualified HVAC technician for diagnosis and repair; do not bypass safety devices or attempt internal gas or electrical repairs.
If you smell gas, leave the area and contact your gas utility or emergency services from a safe location. Never bypass safety controls. Internal furnace servicing should be performed by qualified personnel.
Learn more about the furnace components and operating conditions commonly associated with diagnostic error codes: