Thanks to all who replied. I think I will go out and purchase the
Robertshaw as suggested. The frequent on and off cycling of the
furnace is annoying as well as wearing.

Make sure your contractor checks it out before you spend money that you don't
have too! Replacing the T-stat is a typical homeowner fix to all HVAC woes! 98%
of the time nothing is wrong with the stat! But since I can't see your system
from here, I can only evalutate based on what's told here! Some hot water
systems are set to maintain 180 degree water all the time, and may cycle a bit
in order to do this! I make my living doin this--If I had a dollar every time
the homeowner thought the problem was the t-stat, I would be a rich man! Best
of luck!