Status coded4Rheem
What does Rheem d4 mean?
No valid model data on the memory card. This is a non-critical fault. The furnace should still operate, and d4 is displayed in standby.
Basic checks first: jump to safe DIY steps Equipment type: furnace
How it shows: Dual 7-segment display on a Rheem R96V / (-)96V furnace (installation instructions 92-24161-124-03): d4
Likely causes
- Memory card is blank, missing, or corrupt and cannot be read
- A valid copy of the model data is still stored in the furnace control microprocessor
How to fix d4: safe DIY steps
- If the furnace is heating or cooling and the display shows d4 only while it is idle, that matches the manual: operation should proceed as normal
- Technicianreplace the card with the original card or the correct replacement. The manual says never to use a card from another furnace, condenser, or air handler
Safety firstIf you smell gas, do not touch any electrical switch or use a phone in the building; leave immediately and call your gas supplier from outside. Turn off electrical power at the furnace switch or breaker before opening any panel, and never bypass or jumper a limit, rollout or pressure switch. Gas valve, burner, venting, wiring and control-board work should be done by a licensed HVAC technician.
Capacitors can hold a charge after the power is off. Safety terms.
When to call a pro
Call a licensed HVAC technician to replace a corrupt or missing card. d4 does not by itself shut the furnace down. d1 does.
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