We have a boiler. When we are not home we would like to shut off the water in the house. We have had conflicting opinions about the boiler. We were told that if we shut off water to the boiler and there are any pin hole leaks in the system, eventually the boiler could "dry fire" and have extensive damage. Another opinion said that we could just shut off the valve by the boiler and the water would remain closed in the boiler system. I was wonder if there is another way to handle this issue. Is there a way that we can have a shut off that shuts off water to the entire house, but leaves the water accessible to the boiler, or would doing that cause too much pressure ? I know in doing that if the boiler failed and boiler pipes froze, we would have yet another mess. Your opinions would be greatly appreciated.
Assuming your boiler has an autofill valve (and not all do), if you shut off your water, you could have a problem. Note, normally the boiler should NOT lose water. The valve is there just in case. All modern boilers have controls that should shut them down if there is insufficient water in them.
Yes, if the boiler has a small leak, the autofill might be able to keep up and let it work while you are away, but you then still could have water damage...that water is going somewhere. If it fails to do that, either because you turned the water supply off or the hole was too big, then the boiler should shut down. Now, how well those protection circuits are working is the issue.
If the boiler shut down for lack of water, and it was cold enough, you could be in for much bigger problems.
You might want to install a new valve that would allow you to shut the remainder of the house's fixtures off while leaving water to the boiler.
A good alternative is to have someone check the house periodically while you are away.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013