Thermostat error code

Honeywell Chronotherm IV plus showing “check light” code 2 (two flashes repeating) Any ideas?

I am surprised at how many home inspectors seem to not use Google .

Try this for your needs .

http://cainmanor.com/personal/how-to-reset-the-chronotherm-iv-plus-so-that-filter-stops-blinking/

I’m always surprised by people who think other people don’t try Google…
Been there tried that…