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Sight glass is low (1/5 level). How to refill without cracking boiler?

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I did a few blowdowns without refilling.

Sight glass is around 1/4 high.

Boiler never cold b/c heat and hot water.

What's the best way to refill this back to 1/2 or 3/4 level? (What is ideal level?)

Comments

  • mattmia2
    mattmia2 Member Posts: 15,992

    just do it slowly. if the boiler were empty and glowing that would be one thing but it is already full of water, the cooler water will mix with the existing water. a 1/2" supply isn't going to add cold water at a significant rate in relation to the mass of a boiler.

    ethicalpaul
  • CoachBoilermaker
    CoachBoilermaker Member Posts: 439

    Thanks Matt. I'll just add 5 seconds every few hours. Few times should do it.

    Get it to 1/2 ?

  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 2,545

    Not a problem whatsoever. I have done this a million times. Just fill it to the normal level. No way in the world that will crack the boiler

    ethicalpaul
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 2,545

    Part of routine maintenance, for customers, involves firing the boiler, draining it all the way down, and refilling it. I have done this to more boilers than I can possibly remember, and none of them have cracked. Only way to crack a boiler by refilling, is if the boiler was running on empty, and is cherry red

    mattmia2ethicalpaul