water supply to Furnace BOiler

[mindless06795]

Hello,
If i shut off the main water supply to my house, to do some quick plumbing work, how long can it be off considering my furnace is using the water to heat my house. Should I shut the furnace down for the time I am doing the plumbing?
Thank you.

[LazyPup]

Your heating system is a closed system that should only need additional water in the event that water is lost to a leak. In addition, the furnace should have an automatic low water cutoff switch so you should have no problem with turning the water off for a very short period to make a repair.