LWCO cutting off too soon or ??

aaronlife

I have a 2019 Weil Mclain steam boiler with a Hydrolevel Safguard 400 LWCO and VXT-24 auto water feeder.  The system has been trouble free until just recently when the LWCO will not re-activate the system until we manually add additional water. The sight glass will be a little low, but not too low (see photo before adding water), yet adding some water will trip the sensor and the furnace comes back on.  I’m trying to figure out why adding water to a cold boiler with an acceptable water level turns it back on and why this situation is a recent development. I’m pretty sure I’ve seen the boiler running with only a little water in the sight glass in the past.  Based on the photo is this the sensor level (installed high)?  And maybe my sensor sometimes fails to turn on the water feed or the water feed times out? Dirty probe?  Any suggestions or solutions?  I am out of town so tenant added water and got heat on, just trying to problem solve before calling a tech in if necessary.  Auto water feed is set to LWCO per original installer. Thank you for any ideas 🙏.

ethicalpaul

It's hard to tell with the angle, and I can't quite read the sticker, but why do you think this is an acceptable level? It appears that it might be at or below the "lowest acceptable water level" which is where I would want my LWCO to activate. The "lowest permissible water level" I would think would be below that (and appears to be), and is not where you should generally operate your boiler.

Why the reluctance to keep your water level where it won't trip the LWCO??

Also your water quality looks weird and the boiler may need to be skimmed.

Also how often are you having to add water? If you fill to the halfway point on the glass, I would expect it to take a few weeks or even a month or more for the level to go back to where it is now. Be vigilant for steam and water leaks, they will kill your boiler.

aaronlife

Thanks, I just always thought the acceptable level and lwco probe was lower in the sight glass as notated on the boiler (acceptable is 1/4” above bottom of sight glass).  If it is where it should be on this boiler, then it sounds like my vxt24 has stopped feeding properly intermittently.

Thanks, I do have a leaking radiator coupling in my bathroom I need to fix, I lose steam there, but that’s been on my list for many years. Never troubled the auto feeder. It’s been two weeks since it was last at that level and tripped the lwco.

KC_Jones

@aaronlife Leaks should be addressed ASAP. Leaks cause excess water to be added to the boiler, which in turn shortens the boiler life with the extra oxygen being added.

ethicalpaul

Honestly I would not rely on the VXT anyway and would monitor the level manually, keeping it at about 1/2 to 2/3 in the glass and yes fix that leak. Good luck!

aaronlife

Thanks!

aaronlife

I spoke too soon, tenant thought furnace had clicked and turned on, but it never came on. Turns out lwco had failed. But im glad to learn what I learned here, thank you, will get into the radiator leak as soon as i can.