Rheem Furnace Code D1
Hard lockout
No model data. The control cannot find the electronically stored model data that tells it how to run the blower, so the furnace will not operate in any mode. Usually the model data card is missing from the control board.
Manual wording: “NO MODEL DATA ... This code is displayed anytime there is no model data at the furnace. ... No operation (including thermostat) will be permitted without the model data.”
Documented for: (-)97V, (-)96V communicating furnaces
Likely causes, most common first
- Model data card missing from connector P6 on the furnace control
- The original model data card was lost or disconnected when the furnace control was replaced
When to call a technician
This is a control-board / model-data-card problem. A technician must install the correct model data card for your furnace - the card is furnace-specific and using one from another unit can damage the heat exchanger.
A Rheem furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installation Instructions for Upflow Condensing Modulating, Communicating Gas Furnaces - (-)97V Series (92-24161-126-04) (Rheem Manufacturing Company, R97V series modulating condensing gas furnace (and R98V); TABLE 18 normal operation codes, TABLE 19 fault codes, pages 94-104) · checked 2026-08-25
- Installation Instructions for 4 Position Condensing Two-Stage, Communicating Gas Furnaces - (-)96V Series (92-24161-124-08) (Rheem Manufacturing Company, R96V series and (-)(-)96MDV two-stage condensing gas furnaces; TABLE 19 normal operation codes, TABLE 20 fault codes, pages 111-120) · checked 2026-08-25