Is is normal to not see any water in sight glass while boiler is running?

bipbap

Is it normal to ever see NO water visible in the sight glass while the boiler is running?
I know the water goes down when it turns into steam and off into the system but would it ever be normal to have NO water visible in the sight glass?

FYI, one pipe steam gas system for a 4-family building like photo attached 

Thanks all!

Jamie Hall

Absolutely not. There must be water visible in the glass at all times when the boiler is running -- and the low water cutoff must shut the boiler off if there isn't.

Anything else is really really dangerous.

bipbap

Ok I just turned thermostat down to stop it and so I can see how much water comes back into the boiler.

Earlier today when it WASNT running, sight glass showed half full.
How much should the water level in glass go down when it’s running?

bipbap

It’s cooling down and water level came back to about 1/4 of sight glass 

EBEBRATT-Ed

@bipbap

As @Jamie Hall mentioned when the boiler is firing you must be able to see a water level in the site glass. Firing the boiler with low or no water is dangerous. There are controls on the boiler to prevent this if they are working correctly

Normal water level when not firing should be about 1/2 a gauge glass. When firing it usually will drop a little perhaps and inch or two but not below the bottom of the gauge glass under any circumstances.

If you need a steam contractor post your location or check "find a contractor" on this site. You don't want to have to replace the boiler

bipbap

Thank you all for the info.

At what point should the LWCO activate to shut the boiler? Is that when the water goes down to empty on sight glass?

JUGHNE

When you blow down the LWCO does the fire shut down and then add some water?

bipbap

Well right now I’m waiting to have the water feeder replaced this week.
or should my LWCO be able to add water?

I haven’t tested the LWCO but does this incident suggest it isn’t working? If it got to empty on sight glass should it have shut off the boiler?

I am in touch with a true steam guy about replacing the water feeder so will have him review all
safety components too.

bipbap

Oh and to explain more, when the water feeder stopped working I shut the water supply off to it and have been using the handle to manually refill it as needed while waiting on the new feeder to be installed.

Jamie Hall

It varies somewhat, but generally the low water cutoff should be set to kill the boiler when the water level is at an inch or less above the bottom of the sight glass. If the boiler stayed running with the water level below that -- as it seems from your comments it did -- the low water cutoff isn't working.

That boiler should be turned off NOW with the emergency switch, and not turned back on until you can verify that the LWCO is working.

This is not optional!

The consequences of a dry fired boiler are at the very least, a ruined boiler. You may also have it catch fire. If by some ghastly chance you add cold water to a dry fired boiler, it will blow up.

delcrossv

bipbap said:

?

I haven’t tested the LWCO but does this incident suggest it isn’t working? If it got to empty on sight glass should it have shut off the boiler?

That type of LWCO needs to be blown down weekly using that valve underneath it. It's probably not working.

bipbap

Ok got it.
I’m very glad I caught this when I did.

Jamie Hall

So are we...

SteamingatMohawk

Does your true steam guy know about the empty sightglass? If so, he should have insisted on working now, not this week. A non-functioning LWCO is more serious than replacing the feeder.