Where?!

FredR

I think the reason for "blowing down" while the boiler is firing is to check the LWCO.The burner should stop.This also keeps the LWCO control free of debris.

adambuild

Where?!

I'm drawing a blank! Where does it say that a residential steamer should be blown down weekly to remove sediment and sludge basis WHILE it's steaming so that the particles are suspended in solution. I thought I had seen it in TLAOSH but couldn't find it. A colleague swears that it has to be done when the boiler is off/cold.

DanHolohan

Not the boiler,

the low-water cutoff.

Noel

Confusing, huh?

Since the mud that sticks the float is WITHIN the low water cut off, one vote for blowing down the control while the boiler is steaming.

http://www.mcdonnellmiller.com/Literature/Gen-Tech-Info.pdf

Since the code wants you to test that the LWCO works when the level in the BOILER drops, one vote for lowering the boiler water level with the boiler steaming and the burner running, to see if the burner shut's off when the water in the BOILER reaches an unsafe level.

I'd do both.

Noel

adambuild

?

"Author: Dan Holohan
Subject: Not the boiler, the low-water cutoff."

Thanks Dan, could you elaborate? Do you recall mentioning/writing anywhere regarding blowing down while the boiler is steaming as the dirt particles are in suspension?

Thanks in advance, Adam

DanHolohan

I think it's more an issue

of proving that that cutoff will actually cut off the burner than it is about particles in suspension. It's good to blow it off twice - once slowly (release a trickle) and then again, but quickly. The slow blowoff will often reveal whether there is build-up of crud on the bellows or of the float.