Low Water Cutoff Not Cutting Off

RobO

I have an ITT McDonnell & Miller cut-off on a Peerless Series 61 boiler.  They are both 16 years old.  When I fired up the boiler today and went through some basic maintenance to prepare for heating season, I tried to blow down the cutoff.  But, it didn't shut down when the water level dropped to the point where it normally would.  When I gently wrapped on the side of it with the handle of a screwdriver it shuts down.  When I refill it, it cycles back on.  I have gone through this cycle a number of times.  It seems like the float just doesn't want to drop down on its own.  My question is: is the unit serviceable?  Is there anything more I can try to do to clean or maybe lubricate it?  Or, should I just replace it?

JStar

RE

The float mechanism is replaceable. It is a safety device, so service is not recommended if it fails to shut down properly. No matter how well you think you can clean it and make it work again, it has a history of failure and should be properly repaired. 

Steamhead

And

if the boiler has a tapping for a probe-type cutoff, it's worth upgrading. With no moving parts, a probe-type is much more reliable, and only requires a yearly inspection and cleaning. 

RobO

Where

would the tapping be located?  This is a 16 year old boiler.  Is it likely it would have come with the tapping?

Rod

Tapping for Probe

Look on page 35, Section R, in the I&O manual. It has the locations of all the tappings.

- Rod

RobO

Epilogue

I removed the cut-off, disassembled it and cleaned it.  It was full of muck.  It is working perfectly now.  Thanks for all the suggestions.



Rob