Cleaning your steam boiler?

SUPER DAN P&H

How often should a steam boiler owner remove dirty water from thier system during the heating season? I say once a week to help keep system cleaner. What do you think?

Jean-David Beyer

What would make the boiler water dirty?

I am not a professional, so sometimes my ignorance shows pretty clearly.

This is probably one of those times.



What would make your boiler water so dirty that it would need to be cleaned? The reason I ask is that with a hot water boiler, where the system is not supposed to leak, the advice has generally been not to drain the system as a general rule. You may have to drain some of it if the pH is wrong enough to add whatever water treatment is required. You may flush the system out completely every 25 years or so if you are replacing the boiler.



Now with a steam system, water gets added a little more often because I imagine a little water escapes from the vents (as steam), around the packing, and more often from the LWCO that you drain some water every week. So sometimes you add a little water to make up for all that. Since there are dissolved minerals in the makeup water (more or less depending on the hardness), you may need to drain the entire system once in a while. I have no experience with steam systems, but I would guess that not much dirt comes in this way. So perhaps flushing out the boiler once a year might be appropriate. I suggest doing nothing until a steam pro sees your question and can give advice from practical experience.

Sil

I too am not a pro, but here is my take...

But during heating season one should give a quick flush of the LWCO one ever week or every other week. This is needed to ensure the LWCO will operate properly as gunk can mess it up. Flushing the LWCO to me means two or three quick open and closings of the LWCO valve until the water is more or less clear.



Removing ALL the water from the boiler I dont this is ever really needed - unless major work needs to be done.

Jean-David Beyer

Flushing a steam boiler.

It needs to be done  once in a while to clean out the stuff at the bottom of the boiler. I know that for sure in steam locomotive boilers, and I cannot imagine it is less necessary in a home heating boiler. Even there, you do not empty the boiler, but just flush out enough to get the mud out of the bottom of the boiler. Say once a year. You do not want to wait so long that you cannot do it because there is too much. The "mud" is probably a mix of accumulated minerals from the make-up water, and rust from any oxidized pipe and the radiators of the system.

Rod

Boiler Flushing

Hi- If your boiler is cleaned regularly you shouldn't have to drain your boiler at all during the heating season. When there is snow on the ground outside, is not the time to be working on your boiler!   I drain and flush my system at the end of the heating season and at the beginning of each heating season.  At the end of the season I have a burner man clean and check out my burner's operation. This is a good time to do maintenance as it is the less hectic time of the year for the pros and I think they have more time to spend on my burner.

The beginning of the heating season flush / inspection is to just make sure everything is up and ready for the colder weather and also to flush out the additive that I add to store the boiler for the summer.  (As always bring the new water to a boil to drive off the corrosive excess oxygen!)



Sil mentioned flushing/blowing off the Low Water Cut Off regularly and that is a whole different program. Doing this "blow off" is imperative for your safety and It should be done at least once a week.

- Rod

Brian_74

Don't forget to make some steam

After you've added fresh water, don't forget to fire up the boiler to drive off the dissolved oxygen. If you don't do that, your system will rust quicker, which will cause you to flush it more often, which will cause it to rust quicker….