How Far Down?

Chris M_2

I have a Burnham Megasteam 396. Regarding the waterline when the boiler is running.. How low should I expect it to go before becoming concerned?  What confuses me is that the point at which the LWCO probe enters the boiler lines up at about mid-way on the site glass. The line labeled, "minimum operational water level" - (or something like that) tagged on the side of the boiler is actually lined up about an inch below the lower brass fitting for the site glass. So, am I meant to believe that it's safe to see no water at all in the site glass, as long as the water level is between the "minimum operational water level" and the very bottom of the site glass?  It doesn't make sense to me. I can't see through brass. There's no water hammer at all, and the cold water level is about 3/4 of the site glass. Knowing that all boilers are slightly different in design, I'm hoping someone who knows the Burnham Megasteam can advise, but am always open to learning new things from others.  -Thanks.

JStar

Near boiler.

Are you using both supply taps? Does the boiler shut down on low water?



The water line can normally go as low as the bottom sight glass fitting.

Chris M_2

What are supply taps?

What are supply taps? If you mean fresh water supply, then the answer is no.. There's a single source for fresh water at the lowermost part of the wet return pipe with an electronic autofill that's activated by the LWCO. The boiler doesn't shut down on low water; only thermostat and sometimes pressure. I tested the LWCO by turning the thermostat all the way down, then draining the water. The LWCO kicked in (red light came on) right when the water level was way down, and went back to green when I refilled to the point exactly at the lowermost portion of the LWCO's tapping. Why then, does the LWCO not activate during the heating cycle when the water level shows far below the point at which the sensor kicks on during the test?  Is it because the splashing of the boiling water reaches the probe and satisfies the LWCO that all's well?

Chris M_2

I should have added...

I'm using both taps at the top of the boiler (the two that rise to the header).  The near boiler piping was done by the specs (except for 2 feet of copper joining the header to the main.. I bet the two tappings at the top of the boiler are what you're talking about.. CMannering

JStar

Yup.

I was referring to the supply risers coming out of the boiler. If you had just one tapping used, you could get false readings in the sight glass.



If you aren't getting any water hammer, or major problems, I wouldn't be overly concerned about it....as long as the water eventually comes back on its own and the water feeder doesn't add water every time the boiler cycles.



If you have the factory installed Hydrolevel CycleGuard, there will be a 15 second delay between sensing low water, and shutting the boiler down. Does your water line bounce up and down in the glass a lot when the boiler's running? Or does it just gradually go down throughout the cycle?

Chris M_2

Water Bounce

Thanks for the clarification.. The water does surge a bit.. It goes up and down during the cycle, in a range of about 2 inches, somewhat stabilizing towards the point where the water  level is low, and the boiler shuts off (on pressure or thermostat).  I'm certain that it's not due to oil in the water, as I skimmed this thing after the install on three different occasions, and have not added any radiators or new piping since that time.  The water is rusty colored though.  It looks clear when the boiler is off and settles down, but is brown as bark when the boiler is running. I drained and refilled the boiler at the start of the season, and this bouncing of the water line wasn't a problem after that.  Is the cause of the surging and water dropping so low simply a gradual increase of dirt and rust accumulating in the rads, pipes, and boiler itself?

JStar

Pictures.

Do you have a picture of how your near boiler is piped? What size is the equalizer line? A few things can cause surging.

Chris M_2

Picture

Here's a picture I posted in a previous post.. I'm not at home at the moment, and can't take another, but this might be enough.. Let me know.. Thanks

Chris M_2

I don't think that went through

JSTAR.. If you click on my name (on the left), you'll be taken to some of my earlier posts (different subjects)... The March 18 post 'Cleaning out the Rusty Water" has some pictures..

Chris M_2

Drain, Refill and Boil

All,

FYI.. Yesterday afternoon, when the boiler shut down after a heat cycle, I cut the power, drained the boiler, let it cool for two hours, then refilled and drained 3 times.  The water now stays within a 1 1/2 inch range of motion (1/2 inch above the water line, 1 inch below). The water goes nowhere near the botton of the site glass now, which I suppose proves that the accumulation of rust and impurities collecting in the boiler water throughout the season's heating was the cause of the problem.