Steam Low Water Cut Off Maintenance

rkalber

I own a typical Boston area triple decker with a separate steam boiler for each of the three floors. There are two similar Burnhams and the third boiler is a Crown Jamaica 286 / JS42 (1996). All three boilers have auto-feed.
I've just lost one of the Burnhams, a PIN4SNC-ME2 (2004), to a low water cut off (LWCO) failure. That boiler had a McConnell & Miller PSE-800 probe style LWCO.
The second Burnham has a float type McConnell & Miller #67 LWCO and we flush it regularly.
The Crown Jamaica has a probe Hydrolevel Co. Safeguard # 400 LWCO.
So much for consistency across the systems... but all three boilers were in service when I bought the property.
My question is about LWCO maintenance.
My heating guys say that they don't inspect or clean any of the LWCOs during annual maintenance. Nor do they ever replace them according to the McConnell & Miller recommendation of after 10 years of service life.
So is annual inspection, cleaning, probe replacement (if needed) and 10 yr replacement just an industry CYA and/or should I be looking for a new heating maintenance contractor?

HVACNUT

As long as anti seize compound was used it shouldn't take more than 10 minutes to clean and inspect the probe.
A low water condition should be tested at the maintenance regardless.
If you would like to pay to have a new LWCO installed every 10 years, that's your prerogative.

EBEBRATT-Ed

You need a new heating contractor. As far as the 10 year replacement that's M/M covering their butt. Those controls are safety controls and should be checked and cleaned yearly period, end of story. Every safety control on each of the three boiler should be cleaned and checked yearly. When they need replacement they need replacement. That's one reason I don't care for probe controls, more difficult to test. It's possible they can fail even if they are checked but that is no excuse.

I would call the heating contractor and tell him he's putting in a free boiler because he didn't do his job. I really would rattle his chain

I have worked in MA for years. I know the state inspectors don't cover residential boilers but they would take a very dim view of this

Fred

The MM #67 must be cleaned every couple years (recommended is annual). You need to pull the switch end of that LWCO, Pull the float out and scrape the inner side walls and floor of the cavity. Rust/crud builds up in there and cause the float to hang up on the side walls or not drop to the bottom of the cavity, in a low water situation. It's a relatively simple maintenance task but you do need to order a gasket set to put it back together without leaks. Check the float to make sure it doesn't have a pin hole in it and isn't water logged.

nicholas bonham-carter

It would be a good idea to check for a leak in the wet returns, in case the water leaking out of them caused the low water condition.—NBC

RayWohlfarth

I agree with @EBEBRATT-Ed You need a new contractor. The low water cutoff is the leading mechanical cause of boiler accidents and it should be tested regularly, opened and cleaned yearly, and I like to do the slow drain test which more closely simulates actual operating conditions.