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 blow down

mferrer Member Posts: 33
I understand the importance of blowdowns on steam boilers. On LWCOs they suggest weekly blow downs.
My question is: Do you have to blow down Hot Water Boilers?
Am I correct in stating that most hw hw boilers have electric probe type lwcos and blowing down hw boilers will add fresh water with air and minerals that hurt the system.
However, if dissolved solids come out of the water at around 140 F, do they cause issues in hw boilers if they are not removed?


    EBEBRATT-Ed Member Posts: 15,840
    Hot water boilers are a closed loop (usually) once the burner is fired and oxygen is driven from the water and released through the air vents it is difficult for corrosion to take place.

    Removing a piece of steel pipe from a 40 year old boil will find the pipe in like new condition (if the system has been operated with no leaks)

    I would give the boiler a flush once a year to get rid of any deposits and checking the LWCO probe is a good idea.
  • SuperTech
    SuperTech Member Posts: 2,205
    If you have a dirtmag filter on the boiler it should be "blown down" periodically. It's also recommended to test the pressure relief valve annually, just be prepared to replace it if it leaks after testing, which is likely.