Need advice on Low-Water Cut-Off water feeder

Ziamba

As we are getting deeper into the fall season I decided to go ahead and flush my steam boiler. As soon as I went to operate the blow-down valve on my McDonnell&Miller 51-2 water feeder/Low-water cutoff the blow-down pipe broke off just below the junction to the water equalizing line (see Figure 1 on page 3 of the product manual).

I proceeded to disconnect the junction and was attempting to remove the threaded pipe that connected the float chamber to the junction when this pipe also broke off, leaving a portion of the threaded section of pipe in the bottom of the float chamber.

I'm wondering if there is a simple way to remove the broken and stuck portion of pipe? Or am I better off replacing the whole chamber? Or even replace the whole LWCO/Feeder system?

Big Ed_4

Cut out what you can , then run a tap to clean the threads ..

EBEBRATT-Ed

Like cutting a slice of pie. Make two cuts 1/4" apart with a hacksaw blade. Cut as deep as you can without cutting into the threads in the low water cutoff. Then with a small cold chisel pick out the piece between the two cuts. Then you can collapse the leftover piece in and get it out. Try not to nick the threads if you only nick them a little Teflon tape and pipe dope will seal it up. If you have to make another cut opposite the first two you can but the more cuts you make the more, you risk cutting the threads.

I have done many of these and it just take some patience. You can do it

If you can take the control off the boiler and work on a bench you will have better luck

Mad Dog_2

I'm sorry, but that looks way too clotted up with mud and splooge inside.  I would do a full replacement.  But, if you're that tight for $$$, follow the guys advice.  Cut and cape it out like any other thread.  Just make sure when you're done you test it while boiler is running 🏃‍♂️ and make sure it kills burner and then feeds water.  Mad Dog 🐕 

Lance

Mad dog is right. Considering what it protects, a new one is required. AN insurance underwriter would require replacing it.

ScottSecor

I also recommend replacing entire control.   Based on the condition,  I suspect the connections to the boiler are also clogged up.  Not our favorite type of lwco/feeder, but probably the simplest to just remove and replace. 

EBEBRATT-Ed

Those controls cost a fortune and even the repair parts are $$$$. Maybe replacing it with a Hydrolevel probe type control and a VTX feeder would be more cost effective.

I am sure the old one can be cleaned up and fixed if you have enough time and patience.

Intplm.

Sometimes you don't even need to cut the leftover broken pipe in the threads.
I have tapered, ground down a pipe tap at the tip, and ran it in the threads. Best way to go. Try it. It doesn't hurt the threads and can be a one-step repair.

Ziamba

I went ahead and took EBEBRATT-Ed 's advice on cutting using a hacksaw. However, I accidentally cut quite far into the threads during one of the cuts. I will get a replacement threaded pipe and wrap it up with teflon, see whether it can get a good seal. Back up plan, I go with MadDog's and others' recommendations and look to replace the whole unit. The entire unit is quite pricey though at about 1500. If I can't salvage what I have, what are some good alternatives?

mattmia2

You really need to rebuild that or replace it with the same or a different style like others have said. It needs to be functional and if it is that neglected it needs to be taken apart and cleaned up.

You might want to price an electronic lwco before you start buying parts for the mechanical lwco.

EBEBRATT-Ed

@Ziamba

You can probably buy a Hydro level VXT feeder and a Hydro level low water cut off at Supply House.com for less than the cost of a new MM.