BDP 517EN024010 is driving me crazy

[tgasper]

My problem is wiring a thermostat
I installed the Furnance in my garage. There is only 4 wires on the terminal board in the furnance that is connected ( G , R, W1, C )I bought a Honeywell RTH111 Non programmable thermostat.
I understand where to hook up 3 of the new wires coming off of the thermostat, R to R, G to G ,W to W1, But I'm confused with the 4th wire that connects to C. Any help would be much appreciated

[clay3636]

**"tgasper":* problem is wiring a thermostat
I installed the Furnance in my garage. There is only 4 wires on the terminal board in the furnance that is connected ( G , R, W1, C )I bought a Honeywell RTH111 Non programmable thermostat.
I understand where to hook up 3 of the new wires coming off of the thermostat, R to R, G to G ,W to W1, But I'm confused with the 4th wire that connects to C. Any help would be much */quote:*

this will be your common, check you t-stat to see if it requires a common