Low water cutoffs old and new

John Lenhart

I haven't installed a steam boiler in a few years now and have a question. I was wondering about the new probe type low water cut offs. Most manufacturers don't even have the old McDonnell Miller LWCO's installed on the new units. Is it worth while to have both old and new installed as a redundent backup? Any responses will be appreciated.

nicholas bonham-carter

redundancy

most boilers over a certain size, must have 2 lwco's, according to our local codes. if one of them is the traditional float type, then it will encourage the building owner to inspect the boiler as he is blowing down the lwco at least every other week. he will see the beginnings of potential problems during that time.

i am certainly happy to have the float type because of this!

while you are at it, why not give the customer the option of a vaporstat, and good low-pressure gauge [gaugestore.com 0-15 ounces], and put them on the same pigtail with the code required [but useless 0-30 psi] , and don't forget massive main venting on the returns, if equipped!--nbc

John Lenhart

Low water cutoffs old and new.

This is for a four section 450 sq ft of steam boiler. Natural gas fired. I should of put this in the previous post. So two low water cutoffs are required on large boilers. But are they a good idea for small residential boilers?

Charlie from wmass

I do not use

two LWCO's on residential boilers as seldom does the home owner want to pay the added costs. I think it is a good idea though.

nicholas bonham-carter

how many lwcos

on a small boiler, there may not be the extra tappings for a second lwco. but i would always choose the float type for my boiler, no matter how small, as it would force me to visit the boiler on a regular basis, and check everything.--nbc

will smith_4

LWCO's

John-

It depends on your jurisdiction. Around my part of town (Chicago)-if you have a system larger than 400,000 btu's- you need two LWCO's. Smaller than that, one will suffice. However, my code does not necessarily translate to yours-just check your local code. Redundancy is good in my book-I don't think you can ever be too safe-especially with steam. 

All the Best-

Will