Data not yet on network

What is going on

No data, no run. Control comes up with an empty shared data set, so it will not fire. Almost always a new board or a fresh install. Model data lives on the memory card, not in the board. Right card, right model.

Likely causes

• Control has no data on the network yet, such as after a new board or fresh install
• Memory card missing, loose, or not seated in its connector
• Card from a different model loaded by mistake
• Power cycled before the data finished loading

Check in this order

1. Power off before repair
2. Get the memory card for the specific model. Wrong card, wrong data
3. Seat the card fully, and confirm the model number matches the furnace
4. Insert the card before turning power on
5. Power up and let the data load. Give it a minute and do not interrupt
6. Power off again. Card can come out after load and power-down
7. Error clears once data is loaded and power has been cycled off. If it returns, recheck the card and the board

More furnace guides

• Airflow lower than demanded, furnace runs on low stage when high stage is expected
• Alternate combustion air opening (upflow or horizontal)
• Alternate vent/flue location (upflow or horizontal left)
• Annual inspection checklist
• Auxiliary limit control (location and purpose)
• Auxiliary limit switch open (blower compartment)