I have a circular Heil thermostat, looks like HQ1056302HW and or T87F2915 3. I would like owners manual with wiring layout before I replace it.

The thermostat sounds like a Honeywell. Should have r (possibly rc and rh) g, w, y, and maybe b. Correct? If so, let me know if your furnace is a conventional forced air gas furnace, with or without a/c, or if it is a heatpump. Let me know what color wires are hooked to what terminals on the old stat and we should be able to set you up with the new stat.