Plumber played dumb.
Greetings,
I'd like to bring to your attention something that I think is an example of unsatisfactory (poor) service on the part of the technician that arrived to handle my service request on Wednesday, January 7, 2026. I request service because I had noticed that the low water cut-off on my furnace wasn't working. The low water cut-off is a safety control device that shuts off the furnace if the water in the unit falls below a certain level to prevent the unit from overheating. The furnace is an oil-fired steam boiler for steam radiators. The furnace was installed replacing the previous furnace in 1977. When the Technician arrived, I explained the problem with the low water cut-off to him and also mentioned to him that the float might be stuck because the blow down spring valve handle had been sheared of a few years ago, also, it seems like I have to add water to the furnace a lot more frequently than I used to. The tech then looked over the furnace and said that because the information was worn off of the furnaces data plate, he couldn't read the make and model number also he said if he could, he would not be able to get a replacement cut-off for the furnace because it was so old. I said to him that the data plate is on the low water cut off and I think he should be able to order a replacement part from that. I told him it was a McDonnell & Miller No. 67 Low Water Cut-Off rated up to 20 psi; I further suggested that he see if he could just replace the blow down valve to see if that would allow the unit to function again. He began to blow smoke about needing the model number for the furnace because of pressure settings and indicating that the part needed was obsolete and not available and that the furnace needed to be replaced. I told him that I'll get another plumber to check on the problem before I think about buying a new furnace because it seems like it's just a peripheral unit failure. He said that's a good idea and left. I'd like to mention here that the tech was never rude or discourteous, we were cordial with each other the entire time, I don't question his skill or experience, but he seemed to be dismissive of what I was trying to explain to him or anxious not to really check to see if he could solve my problem. That's the impression he left me with, but I leave room to be mistaken.
Anyhow, that same evening I did a little research and found that the McDonnell & Miller No. 67 low Water Cut-Off is a very common item used on old & not so old boilers. and that it is readily available at quite a lot of part suppliers & other sources. new, used, and refurbished, and so is just the blow-down valve. I ordered a refurbished unit (at a really good price). On Saturday, January 10,2026 I removed the blow down valve from it and installed it on the unit on my furnace and after a lot of flushing to get the goo out I could hear the float functioning. I installed some new piping on the unit to channel water into a bucket. It worked just like it used to, actually better. I then investigated and found that two of my seven radiators were leaking at the steam valve connections, so I reseated them with some fresh sealant. Then, I found that two of my radiator air vent valves were not closing and continuously releasing steam. I replaced all the radiator air valves; these two problems were why I had to add water to the furnace so often. Remember I mentioned to the tech that I had to add water more frequently; I guess it didn't ring a bell. My heating system and furnace seem to be working just fine now.
I can't speak to the tech's skill or experience, but I felt that he was impatient or wanted a quick and easy job. I had asked other techs about replacing the low water cut off or blow down valve when they did annual tune ups, they said I needed to make another service call for it, and I couldn't keep it on my mind. I'm 64 and twice retired and I'm fairly familiar with boilers from some work experience but I like to rely on professionals for somethings (like my family's safety). I just wanted you to know about my experience in case you care. I felt kind of blown off and abandoned. Gee, it's cold out there.
I attached some pics of the job I did.
Sincerely,
Ellery Queen
2462 Lakeview Avenue Baltimore, MD 21217








