Auto Water Feed adding water when not needed - Steam Boiler

camsplace19

I had an event last night where the boiler all of a sudden started making loud noises. It had been running fine for about an hour. I believe the Auto Water Feeder added water while in operation. I've never had to add water before and running it last week I had about 1.5 inches of water level in the glass. Last night after I heard it, the glass shows about 2-3 inches of water, and the digital display on the feeder increased an increment.
Questions:
1. I understand the Auto Water Feeder purpose, but should it be adding water to a hot boiler?
2. What could cause the feeder to add water when it appears none was really needed?

For the time being I've closed the water valve to the feeder so it doesn't add cold water again without me checking it. I can add if needed and I assume the low water check will turn the boiler off if necessary.

thanks for any info or insight on this.

KC_Jones

The level in the glass should be at the middle of the glass, unless your gauge glass is exceptionally short, 1.5" is really low. At that level you could be running right around the LWCO setting and that may explain the feeder adding water last night. The auto feed will add whenever the LWCO calls for it, temp of boiler doesn't matter.

Jamie Hall

This ^^^

camsplace19

Thank you for the quick response. Is adding the water to a hot boiler not an issue? I read some articles about waiting for it to cool so as not to damage the boiler. But if it's an auto feeder I guess you can't control that.

EBEBRATT-Ed

@camsplace19

Operating a steam boiler is a "hands on" not a "hands off" operation. You should be checking the boiler at least weekly doing a visual check of the water level and checking for leaks and any unusual operation.

As @KC_Jones mentioned normal level of the water is 1/2 a glass not 1 1/2 "

KC_Jones

Normally you don’t want to shock hot metal, but it’s not a hard and fast rule and it is really a matter of temperature differential.

If you add manually, do it while the boiler is firing, that way it helps boil off dissolved oxygens right away, and it lessens the thermal shock as you are adding heat while adding water.  The reality is, the volume of cold being added is so small compared to the volume of hot, it shouldn’t be a problem.

camsplace19

Thanks everyone, for the info. I'll keep an eye on it.

dopey27177

You speak about knocking when the feeder feeds cold water into the boiler. It sounds like the water supply line to the boiler is not connected to the wet return side of the boiler. (lowest pipe connection in the boiler.)

Jake