Manual Reset LWCO and Weil-McLain EGH Boilers

My EGH came with a Manual rest LWCO (M&M 802) which was installed in the recommended tapping. I added a #67 (auto) using the usual sightglass tappings. This resulted in the manual reset LWCO was higher than the auto rest #67. The LWCOs were upside down. I ended up buying an auto reset 802 and a manual reset switch for the 67. It's only money!

The EG/EGH series (and the SGO series too) still has 1/2" try-cock tappings next to the sight glass. We use Hydrolevel 1/2" LWCO probes in these to add the second LWCO.

Does anyone have any credible information on how/if a secondary LWCO actually comes into play? What have been the circumstances that caused it to do its job?

SteamingatMohawk said:

Does anyone have any credible information on how/if a secondary LWCO actually comes into play? What have been the circumstances that caused it to do its job?

If the automatic LWCO is properly maintained then you will never have a problem where the manual reset LWCO is needed. And since every steam boiler owner spares no expense in proper maintenance on their steam equipment, then there is no need for them. But the exception to that rule about every steam boiler owner is greater that you might think. What if a building owner has an automatic LWCO like the float type, and perhaps they neglected to flush the float bowl weekly for a couple of months. that float bowl might get some buildup in there and continue to allow the burner to fire even with the low water condition. They might be glad to have a no heat call with a manual reset LWCO and not have a no heat call with a cracked boiler section.



And if you have two electronic LWCO devices, the one that gets the most use or cycles will fail before the one that hardly ever cycles. There have been rare occasions where a perfectly good LWCO with a perfectly good probe, has an electronic component fail. I'm think that both of them failing at the same time is slightly more rare. The one that cycles regularly as an operating control that may also be connected to an auto water feed valve would fail first. But I only had about 10 to 12 steamers in my customer base and the one where the manual reset LWCO did its job was on a church with a float type auto LWCO. The church elder that took care of the weekly flushing of the LWCO was hospitalized and forgot to have someone else do his weekly boiler thing.

One Sunday morning I got the call and found the problem quite easily. Flushed the LWCO and lots of mud came out of the blow off valve. The following week I met with another church elder and we opened up the LWCO and thoroughly cleaned the body of the float chamber. They did not have a problem with the manual reset LWCO ever again.

Mr. Ed

JohnNY said:

Steamhead said:

The EG/EGH series (and the SGO series too) still has 1/2" try-cock tappings next to the sight glass. We use Hydrolevel 1/2" LWCO probes in these to add the second LWCO.

Looking through their catalog, I don't see a model with a manual reset. Can that be? I'll give them a call.

You have to supply and install it. Unless something has changed recently, W-M has not embraced probe-type LWCOS the way they should. The LGB series, for example, lacks suitable probe LWCO tappings. But the 80 series has a try-cock tapping that will accommodate a probe.

Given the way people don't maintain float-type LWCOs, it makes no sense to use them anymore.