I have a 90 year old brick & frame home in Canada. The house is heated
by a new, natural gas water boiler furnace with the original radiators.
I have installed a modern variable temperature thermostat that allows
for the temperature to be changed based on the time of day. I have the
temperature set to rise to 70 degrees when we are home & go to 60
degrees during the day & evening when we are out or asleep
respectively.

I have been told that it is more efficient from a wear & tear & cost
optimization perspective with a water/rad system to keep the
temperature at a constant degree setting, as opposed to chaning the
temperature throughout the day.

Can someone give me some advice?...particularly important since the
cost of natural gas is going through the rook this winter.