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One of our techs told me he had an oil pump go bad on a Weishaupt burner on a Viessmann boiler last Thursday night shutting down the heat in a school. This is a 2500mbh boiler. Yeah, they have an old Burnham that they only use for a back-up so they limped by ok.
He just got a pump today, made by Suntec in France. They had to fly one in. Their were none in the USA.
I don't know what the impact of parts availability is on the residential equipment because I don't do much of that but on the commercial side this is a real issue. I have had several problems with this.
I admit that the Viessmann, Buderus etc equipment is good equipment. Set up properly they run for long periods of time efficiently and with a minimum of service
But anything mechanical can and does break. No matter how efficient they are over and above "standard USA equipment" no amount of fuel savings (and were only talking the difference between the two) can offset the cost of down time, parts cost and aggravation
At least in my opinion