LWCO help

JoeSchmoe

Last year I became a proud owner of Burnham PIN5SNC-ME2 manufactured in 2003. I cleaned the combustion chamber and burners, preemptively replaced thermocouple and removed and checked the pigtail for obstructions. Everything is good here.

It has McDonnell and Miller LWCO with no model number that I can see on the housing that also controls the automatic water feeder.

Several times during the winter months the LWCO was malfunctioning i.e. red and green light were flashing and the relay was clicking while the water level was well above the probe. Power cycling the boiler was bringing it back to normal operation. I want to replace the probe and see if that takes care of this problem. Judging by the condition of the burners, I suspect it's never been replaced.

What's the correct probe for this application?

Also, several times I noticed the LWCO making repeating ticking sounds, kind of like a mechanical clock, with no other symptoms. Usually a light tap or two on the housing made the sound stop. Is it something to be concerned about? Maybe it makes sense to replace the entire LWCO together with the probe? If yes, what's the proper replacement?

109A_5

"Usually a light tap or two on the housing made the sound stop."

Maybe a loose connection inside.

STEAM DOCTOR

Very unlikely that the probe is the cause of the problem. I would suggest replacing the whole water cutoff. It's a pretty important component!!!!

mattmia2

i would be worth it to pull the probe and make sure it and its connection to the inside of the boiler is clean. it isn't by any chance doing what it is supposed to because the water in the boiler is surging or something like that?

STEAM DOCTOR

Boiler water surging, is unlikely to cause the low water to cut off to click. And certainly would not be resolved by pushing the body of the low water cut off. All signs point to an electrical issue

JoeSchmoe

Thank you gentlemen. I guess I'll be replacing the entire LWCO.

Is PSE-802-24 what I need?

Is it plug and play?

STEAM DOCTOR

No longer manufactured. Might as well get a hydrolevel safegard.

109A_5

Did you at least take the cover and inspect the wiring ?

You stated "Usually a light tap or two on the housing made the sound stop."

Maybe a loose connection inside.

leonz

In my speaking as a home owner,

I purchased a McDonnel and & MIller RB-122-E low water cut off for my coal stoker boiler used in hydronic heating and it has performed flawlessly for 10 years now.

I replaced 2 defective hydrolevel 3250plus units and do not regret it.

As you have a steam heating system McDonnel and MIller recommends that two 120 volt RB122-E Low Water Cut off Switches be installed in series connection as the first electrical controls to protect the steam boiler.

Your low water cut off sensor has the self cleaning swivel on the probe like my RB-122-E.

It would not hurt to vacuum inside the cover or use compressed air to blow out any dust that may have accumulated too.

McDonnell & Miller has many 24 volt Low water cut off switches available.

As 109A-5 has mentioned perhaps you should take the cover off and check for a loose wire and or a spider web or dust build up before you do any repair.

Based on what McDonnel & Miller has stated in its literature installing two 120 volt Low Water Cur Off Switches in series connections (in my case) to control the boiler will more safely control the boiler and provide more protection in the event of a low water condition.

If you decide finally that you want to replace the existing Low Water Cut Of Switch be sure to take the switch cover with you to obtain the correct replacement unit or two equivalent RB-122-E 120 volt Low Water Cut Off Switches to replace it with the correct lengths of 120 volt BX cable.

The use of a 120 volt Low Water Cut Off switch eliminates the 120 volt to 24 volt transformer.