I foolishly got myself into this mess. Any suggestions?
1923 house with original steam heat (gas). The addition (~1998), has hot water (baseboards). I tried to replace the addition's thermostat, and got myself into a situation...
The addition had one of those old dial Honeywell mercury thermostats. After removing it, I was left with 4 wires (here) - black, red, yellow, green.
My new thermostat is a Honeywell RTH2300B, and calls for this wiring, which is white, red, yellow, green. After much discussion with Honeywell's support and some online research, I decided to take a chance and see if the black would substitute for the white. Here's what I did: photo. Yes, I'm an idiot and don't know what I'm doing.
Anyway, I clicked the front of the thermostat on (with the power switch off), and my heat turns on. The only way for me to turn the heat off is to take off the front of the thermostat, so it's like this.
So, my question is: other than trying to get an electrician here on a Sunday of a long weekend, should I try another wiring configuration?
Any suggestions? Thanks. It's going to get down to 18 deg F tonight.