old boiler question

john_181

Is it better for a boiler to fire a couple times and hour to keep the same temp maintained? Or is it better to have a little swing, say +/- 1 degree. I am trying to set the cycling of my old boiler. (big system, 1 zone, 430,000 BTU 28 rads, large pipes)

please provide me with some input - THANKS

Unknown

john

That`s a very broad question.
Comfort is the key issue in our profession.
Are you looking at the point of fuel economy?, most everyone is but remember, comfort is paramount.

Dave

Brad White_202

So many other ways to improve performance, John

Generally, the fewer cycles the longer the boiler will last and the more efficient it will be.

Every time a boiler fires (an angel gets it's wings)..ah, sorry, no, wrong story.

Every time a boiler fires, it goes through a period ranging from 30 seconds to two minutes, sometimes more, during which the combustion stabilizes, CO drops and the flue passages warm up. This happens each and every cycle, so the more cycles the lower the efficiency.

If you were to use outdoor reset on the boiler or better yet, decouple the radiation loop and use injection pumping, you would do far more than cycle control would do.

Your cycles would be incidental to the heat load and with a good outdoor reset control, would be given a differential around which to operate; basically the boiler will fire and stop firing at a floating variable temperature above and below the boiler setpoint. This will keep cycling to a minimum and with constant circulation, comfort will increase in the bargain. Such a deal.

Steamhead (in transit)

Is this

a steam or hot-water system?

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Brad White_202

Hot water, as I recall

If I am not mistaken, this is the large-pipe formerly gravity HW system in western PA? The old store now apartments?

john_181

YES it is - hello Brad, I did not have your eamil so I figured I would post a question and see what happens. The system is good thus far. Just trying to make it run a bit longer and make it a more even heating and less gas used if i can. Please email me so we can chat. jwmirz@aol.com

THANKS