Denso Air Conditioner Error Code E01

E01 indicates that the WMC room thermistor (RTS1) has been detected as shorted or open by the control system. The thermistor is responsible for measuring indoor ambient temperature, and without a valid reading the unit faults and stops operating. The prescribed repair is replacement of the WMC assembly, though wiring and connectors should be checked first.

No. When E01 is active, the unit has shut down because it cannot obtain a valid room temperature reading. Attempting to force the unit to operate without a functional thermistor can lead to improper temperature control and potential system damage. The fault should be resolved before resuming normal operation.

A power reset may temporarily clear the E01 code, but if the WMC thermistor (RTS1) is genuinely shorted or open, the fault will return as soon as the unit performs its self-diagnostic routine. Resetting without repairing the underlying hardware issue is not a long-term solution. The root cause must be addressed to permanently clear the error.

Checking and reseating connectors is within the capability of a knowledgeable DIYer, but replacing the WMC assembly involves working with electrical components inside the indoor unit. If you are not comfortable with appliance electrical work, a qualified HVAC technician should perform the repair. Attempting repairs without proper knowledge of the system can cause additional damage or personal injury.

Repair costs depend on whether the issue is a simple connector problem or requires a full WMC replacement. Labor charges for a service call typically range from $75 to $150 or more depending on your region. WMC parts costs vary based on the specific Denso model, but budgeting $100 to $300 for parts plus labor is a reasonable starting estimate for a full WMC replacement.