How do I troubleshoot heating that won't turn on?

First, check that the thermostat switch is set to HEAT and verify the system fuse or circuit breaker. Confirm correct wiring and good connections. If still not working, jumper wires R and W together—if heat does not come on, contact your heating dealer. If the display is blank or shows bAt Lo, install fresh batteries. If the temperature setting is higher than current temperature and the display shows HEAT, contact Honeywell Customer Assistance at 1-800-468-1502.