Basic homeowner question here so be gentle...
I'm replacing the old murcury thermostat with a programmable digital to
hopefully same some $$ on oil. It is a very basic system - oil fired boiler
with baseboard heat; one zone; no A/C; no fans etc. The old (and I mean old)
wiring is two wires, white & black. From what I can gather, one wire goes to
the Rh terminal for "Heating power supply and one wire connects to W
terminal for "Heating Signal". Questions is, does it matter which wire goes
to which terminal?? The old thermostat has no markings in regards to what
the wires or terminals represent so I can't copycat the instillation. My gut
says white wire to Rh for power and black to W but I'd prefer not to have my
gut destroy my $5000 boiler.