Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Boiler water feed shutoff

I bought a cottage, that has a Slant/fin Victory 90 boiler, in a cold northern climate location and I'll be visiting the house on average once a month during winter and I'm unsure if I turn off the main house water pump for a few weeks would that be a issue to the boiler system. Why would I turn of the main water pump? its the fear of a water line freeze. I'll be setting the house temperature to 58 degrees while I'm gone. I understand the boiler has a closed water system and it does have a valve to accept more water if needed but would the boiler require new water over a 3 to 4 week period.


  • BBros
    BBros Member Posts: 41
    edited October 2016
    Anecdotally, I would say the risk of the furnace quitting on a fuel or air issue and the house freezing is greater than the risk it will lose water and trip out on lwco... and freeze. Heating systems really ought not be "consuming" water. IF they are, you are potentially damaging the system with the constant in-flow of oxygenated water.

    As you may know, turning the water main or pump off doesn't protect against freezing. It protects against thawing! The danger is the pipe bursts due to freeze up, then floods the house once it warms up...

    I would shut off the water if there is genuine concern a pipe might freeze up, particularly if you think it might freeze up regardless of the boiler operation. I would also say... figure out how to insulate the risky piping!

    I'm not a pro though, so wait for someone more qualified to answer.
  • Leon82
    Leon82 Member Posts: 684
    Assuming it is sealed good it will be fine, also assuming a low water cutoff is installed.

    I would close the valve for the autofill. It should have a back flow preventer but better safe then sorry.
  • Jamie Hall
    Jamie Hall Member Posts: 19,106
    If you turn off the water -- perhaps not such a bad idea -- be sure and drain all the domestic piping thoroughly. As @BBros noted, the real hazard is that something will freeze and burst the pipe -- and then when the water is turned on or thaws you get a flood. Don't ask me how I know...

    The heating system is a different matter. If there is no low water cutoff on the boiler, though, you should turn it off if you turn off the rest of the water. If there is, however, you can safely leave it running even with the water supply turned off. There are two possible problems: if there is a leak in the heating system, it might shut off on low water, and freeze. Which you don't want -- so check and make sure there are no leaks. If the power goes out, it might also freeze... the solution to both of those is to add antifreeze (glycol) to the hot water heat. That will make future repairs on the system a nuisance, and you should have a backflow preventer on the feed to the boiler, but it may be worth the effort.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • BobC
    BobC Member Posts: 5,310
    You can install a freeze alarm that will dial a phone number if the temperature falls below a preset level. At least then you would know if there was a problem.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • tntschmidt
    tntschmidt Member Posts: 2
    Thanks for all of the knowledge and tips/ideas. I need to confirm a few things about my system and then come with a protocol for when I'm away for the house.