How do I clean a model 67 LWCO?

sbelyo

I have a M&M model 67 LWCO and it is not working.  I never realized that I should be doing a blow down from there.  The installer actually put a plug in the bottom of the valve and said as long as I kept the water clean I'd be ok.

Fast foward ten years and I now have a problem.  The LWCO is not functioning, I suspect it's clogged up.  It has the old valve at the bottom with a knob.  I can't open it as you can hear it being blocked by sludge. 

I ordered a new ball valve 14B from pexsupply.  Replacing this looks straight foward.  My plan is to see if I can get a flow through there and try and flush it out.

What's the best way to approach this?

Unknown

i hope

I hope you fired your installer and didn't pay him the last visit!

nicholas bonham-carter

Step 1

Turn off the boiler, and drain it until the waterline is just below the bottom of the glass. Remove the wiring from the screw terminals of the LWCO, making some notes to yourself how they were connected. Undo the union nuts which connect the LWCO to the sight glass piping. The LWCO can now be removed, and put on the bench. Put some plastic garbage bags under it on the bench, as what will come out is very dirty.

There are 4 screws holding the old valve chamber onto the main body, and when undone, allow the float chamber to be opened. Dip the non-electrical end in some soapy water, and clean the goop out from the float chamber, while avoiding any regrets about not having ordered a complete replacement LWCO, instead of one little part!

Clean the mating surfaces thoroughly, and then reattach the new valve body to the main casting.

Remount the whole LWCO onto the sight glass piping, and reconnect the wiring. Turn the boiler back on, and test the LWCO for cutting off the burner as you open the valve holding a bucket underneath. Most of the time the valve should be held open until the mud coming out changes to weak tea, and then closed.--NBC

rrg

Video

I don't know the model but I did come across a LWCO in a video and you can look at 26.00/44.45 mins into the video on youtube.



"Steam Boiler Clean and check Day 2"



Hope that helps to give you a better visual of what happens.



TIP: I always use a camera and markers (sharpies) to take pics and label items before I remove or dismantle anything.

Hap_Hazzard

Here's your manual

And the parts manual.

sbelyo

Next steps

thanks everyone... I'm gonna watch the video to see if I can figure out how to get it off. I read the manual a few times but i'm not sure if I can get the bottom connection off. I'll have to watch it being done.



I did trust the original installer mainly because he's a good friend. I should have done more research so the lack of a working blow down valve is partly my fault.

nicholas bonham-carter

A good friend

Would he have remained so if the boiler had dry-fired due to the LWCO not functioning?--NBC

sbelyo

I think I saved it from a dry fire

I'd be at a loss for words for sure.  However, I'll provide a little detail.  The LWCO failed Saturday morning.  There was very very little water in the system.  The radiators had steam in them, the house was up to temp.  The smoke detector in front of the boiler room went off due to the rising heat.  The burner was cut off.  I put an IR thermometer on the cast iron above the burners and it read 224 F.  the cast Iron section above it read about 20 cooler.  I let the system cool for three hours.  House dropped to 59.  I filled it to the correct level with hot water from my water heater.  waited about 15 minutes.  No leaks, no hisses.  I let it fire up watching it for leaks.  After a few minutes steam began to build.  The radiators all had steam.  Still no leaks, water was clear in gauge glass.  House was back up to temp shortly there after.  I have been checking it twice a day for the last five days and it's still operating normally.  The LWCO is still not functioning.  I have the valve arriving today and will replace it tonight so that I can attempt to flush it out and see if the LWCO can be saved.  Do you think I caught it in time?

sbelyo

It is fixed

I removed the old spring valve, disassembled the float and switch. Cleaned out the pre-historic mud. Re-installed the float and switch. Installed a new 14-B blow down valve. LWCO now works like a charm. If I can do it, so can you

Jamie Hall

You are one very lucky puppy

but if the boiler hasn't shown problems by now... you may well have caught it in time.  And, bless you, you didn't just hit it with cold water.  Good sense, there.

sbelyo

Amen to that

We appear to be in the clear. I also fixed a leaky valve on the first floor that I had closed off and a main vent that did not work. Those two problems caused the boiler to work twice as hard and become over sized. I wouldn't have fix all this without this site

Hap_Hazzard

Luck had a lot to do with it.

When I took mine apart a few years ago there was so much corrosion inside I could see it was a lost cause, in spite of having done weekly blow-downs. I can see why they recommend replacing them every 10 years.