What It Means
- SLP98UHV, SLP99UHV: No 24 Volt output on Y1 to C with non-communicating outdoor unit.
- SL297UHNV: No 24 Volt output on Y1 of ”integrated control” with non communicating outdoor unit.

Ducted Heating
E347 means different things on different Ducted Heating models. Enter your model number to see only your reading, or find your model below.
Models: SLP98UHV, SLP99UHV
Y1 relay / Stage 1 failed (Pilot relay contacts did not close or the relay coil did not energize).
No 24 Volt output on Y1 to C with non−communicating outdoor unit.
No 24 Volt output on Y1 to C with non- communicating outdoor unit.
Models: SL297UHNV
Operation stopped. Y1 relay / Stage 1 failed. (Pilot relay contacts did not close or the relay coil did not energize; no input back to IFC chip). Critical Alert. Cleared after reset and Y1 input sensed.
No 24 Volt output on Y1 of ”integrated control” with non communicating outdoor unit.
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