Boiler at a part time 2nd home & programable thermostat

[pit monster]

My wife works away from home during the week and we recently purchased a 2nd home that she is in Monday evening about 5pm through Friday morning about 8am.

It is a 1923 bungalow with a brand new New Yorker oil fired boiler running cast iron radiators throughout the home (Yeah the old boiler gave up the ghost the week after we settled on the property). There is insulation above the first floor ceilings (10 ft ceilings at that) and the 1/2 second story is fairly well insulated with one radiator on the same zone as 1st floor.

I currently have it going back to 55 degrees during the unoccupied time frame, warming to 68 degrees around 1 pm Monday afternoon and then to 72 by 5:30 pm. I also set it back to 68 during the weekdays and 68 at night with a couple hours at 72 in the mornings before she leaves. I am using a Honeywell 7 day programable t-stat.

What do the experts here recommend regarding setting back the thermostat for the 2 1/2 days the home is unnoccupied? What are your thoughts on dropping back 4 degrees during the workday and night time while sleeping?

[johnjh2o1]

If it is a old home then the chances are that there are heating lines in the outside walls. If it happens to be real cold when the thermostat is turned down it will be a long time before the heat comes on again, giving the lines in the outside walls a very good chance to freeze.

John

[pit monster]

None of the lines are in any outside walls. I can see all the plumbing in the basement and all the lines stay there until they pop up through the floor to the radiators in the first floor.

The lines for the 2nd floor radiator do run through an attic space for about 3ft or so.

This hydronic heating stuff is all new to me. We have oil fired hot air in our other home and it warms up rather quickly if I set it back while away for a weekend.

Is there freeze potential during the time frame on Friday's dropping from 72-55 degrees?

[Doherty Plumbing]

Is there freeze potential during the time frame on Friday's dropping from 72-55 degrees?

Not if the lines are exposed to the heated space.... However if you're worried about I would put some glycol in the system (10-15% of the volume). But glycol is expensive -- then again so is a flood.