Recirculation Pump Motor

  My mom's house uses hot water that circulates through pipes in the concrete slab to heat the house. Its excellent heat - best mechanical heat available. The water that gets heated then gets circulated through the pipes over and over and over again, for decades. So it recirculates the water. Sometimes, the electric motors that recirculate the water wear out and stop working. In the summer of 2013, I discovered that one of the motors was not working. So when it got cold, I figured I should look into repairing it. And since a heat/plumbing outfit would charge about $1000 for a new motor and the time for their youngest, least experienced technician to learn how to almost fix it, I figured I could learn on my own nickel.

  Click for a Larger Image These are hot water recirculation pumps (in back) with electric motors propelling them (in front). Note the one on the right doesn't have any wires connected. When I connect the wires, its sparks and smokes and smells funny.

  So I unbolted the motor from the pump. In between the motor and the pump is this drive isolation system. The shaft of the motor (not shown here) goes into the metal thing laying in the bottom and the allen bolt is tightened into the shaft. Then, when it spins, it pulls on the springs which elongate a little in the event the pump shaft is a little resistant to get going. Once its moving a little, the springs retract and everything spins at the same speed. Very ingenious. Probably invented in the 19th century. Elegant. Simple. Reliable. It's so 1920's! Click for a Larger Image

  Click for a Larger Image Here is the side of the bad motor. Its made by Bell & Gossett, Model 111034. This one (and most every one still in the water recirculation business) has been rebuilt by Sid Harvey, after which they are known as an A28-15R. They generate a whopping 1/12 horsepower at 1,725 RPM. It would take 1,680 of these things to equal the power of the Scooter at 10,500 RPM. Of course you could buy 400 of these motors (at retail) or one Scooter.

  The new (rebuilt) one is all installed here (on the right). Note the careful cable routing. I guess when we wire in the utility room, the whole room can be considered a "box." I used longer bolts on it as well so that there was more than one or two threads in the motor. Nice having bolts in my inventory. Click for a Larger Image

  Click for a Larger Image Check out the little drive line whirring away. The new motor, on the right, is whipping those spring things around and that's turning the pump, recirculating warmed water through the pipes under the floor and warming the floor, just like it did when I was a little kid and would lay down on the floor in the bathroom when I was sick cause it was warm and I wouldn't have so far to go in case I had to sell some Buicks to Ralph.

Circulate some Mail my way