Forced HW heat/Indirect HW and shutting your water main on vacation

KC1

Hello everyone-

A couple of weeks ago there was a leak in my bathroom that sprung which was quickly identified and fixed. It was real good timing because my wife and I just returned from a long vacation, and if that leak started a few weeks earlier, a $10 fix would of been a bigger problem. This situation got me thinking about whether I should close my water main while I leave the house for a prolonged period of time...

So I asked the Tech who was at my house last week completing a tune-up to my Buderus boiler that powers my forced hot water heat and indirect HW for his thoughts. He told me that there is risk to the heating/hot water system associated with turning of water main (especially during the heating season), and installed for me 2 ball valves that will enable the heating system (including hot water from my indirect heater) to operate normally, but cuts off hot and cold water to the rest of my house. The first is on the cold line a couple of feet after the boiler system. The 2nd is on my hot line, about a foot or so from where hot water exits my indirect water heater.

Two questions:
1) Do you agree that there is risk associated with shutting off the main water shut off to my forced hot water heating and hot water systems? I just would like to know if whether I still have an option to completely shut water off to the house if needed.

2) The plumbing in my house if sort of old (~80's), but I was kind of surprised that the system did not have the 2 ball valves the tech installed. Just wondering "why" that this is the case-perhaps oversight? Is there any harm in having the new ball valves installed in the aforementioned locations (I would assume "no")?

Thank you.

HVACNUT

I've seen the separate branch to the boiler feed before the main. But some recommend leaving the valve to the pressure reducing valve off all the time anyway. Once all the air is out of the system, it shouldn't need water. And the tech will check it annually. 
Your boiler should have a Low Water Cut Off to prevent dry firing. 
If your gone and the house main is off, but still have available water to feed the boiler, then spring a leak in a heating pipe, then what?
If I leave for an extended period, I close the main. If it were winter and had nobody to house sit, I'd drain all the domestic and put antifreeze in the traps while leaving the boiler to rely on the LWCO.

EBEBRATT-Ed

Shut it off at the main, shut the boiler and water heater off.

If you leave during cold weather, you will have to drain and antifreeze unless you have someone to check the house

KC1

Hey everyone- I should of mentioned--we have 2 cats and live in New England, so winters are cold, and we can't shut the forced hot water heat off. We will have someone coming to the house however every 3 days or so for the cats. The plan would be to shut the ball valves that cut the water to the rest of the house but not the heating or indirect water system. We will leave water in containers for the pet sitter.

Larry Weingarten

Hi, Another approach that @hot_rod has mentioned is to install a pressure tank in the heating system. This becomes a source of makeup water when the main is shut down. It also minimizes to amount of water that can leak out should something fail.

Yours, Larry

Jamie Hall

KC1 said:

Hey everyone- I should of mentioned--we have 2 cats and live in New England, so winters are cold, and we can't shut the forced hot water heat off. We will have someone coming to the house however every 3 days or so for the cats. The plan would be to shut the ball valves that cut the water to the rest of the house but not the heating or indirect water system. We will leave water in containers for the pet sitter.

That works, and it is what I would recommend. With this addition: pay your cat sitter enough so that he or she will come at least every other day, and after any storms, and make sure the house is secure and the drive plowed and access to the oil tank -- if you have one -- maintained. It won't be that much more expense, and it can give a great deal of peace of mind.