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AFG motor won't run with pump bolted up

870 Views 8 Replies 3 Participants Last post by  BOUTYM
Have an older AFG burner with a centrifugal pump coupler on a model 68 boiler. I had to pull the pump off and when I put the pump back on everything seemed to go back together smoothly. Slid right in and whole assembly rotates freely. Tried to fire it up and the motor wouldn't run. If I loosen up the pump to the point that the pump is about 1/8" off the mount it will run, but obviously clatters a bit. Tighten up the pump bolts and the motor will stop rotating.

I can't see any interference anywhere and again everything rotates freely with the pump mounting bolts tightened. What the heck did I miss or mess up?
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Have an older AFG burner with a centrifugal pump coupler on a model 68 boiler. I had to pull the pump off and when I put the pump back on everything seemed to go back together smoothly. Slid right in and whole assembly rotates freely. Tried to fire it up and the motor wouldn't run. If I loosen up the pump to the point that the pump is about 1/8" off the mount it will run, but obviously clatters a bit. Tighten up the pump bolts and the motor will stop rotating.

I can't see any interference anywhere and again everything rotates freely with the pump mounting bolts tightened. What the heck did I miss or mess up?
any chance you missed a washer when you pulled pump....something is binding up when you tighten it down...if runs fine 1/8" off mount and you can't see any other problems or find out why its doing that....install washer to keep it 1/8" out..ben sr
A missing washer or gasket or something was my first thought, but I don't recall anything falling off or out. I looked inside and found nothing laying in there. I think tomorrow I'll pull the motor/fan assy out and see what I can see. It has me baffled for sure and I can't find a breakdown of this particular burner to see what should be there. All the breakdowns I've found so far have the newer style coupler.
Pump coupling is probably not lining up right.
Lining up with what, the shaft(s)? By the looks of it you can't really mess it up. Well, I probably did, but I'm not sure how it would line up differently than it is considering the flats on the shaft. What is completely baffling is that I can freely turn everything by hand with the pump fully tightened.
loosen pump, runburner, then tighten pump again. If burner stays running, plus you can shut off the burner and then it restarts like it should. the clutch was out of straight alignment with itself.
loosen pump, runburner, then tighten pump again. If burner stays running, plus you can shut off the burner and then it restarts like it should. the clutch was out of straight alignment with itself.
This also I suspected and attempted. No go. Motor will continue to run, but then will not start up again unless I loosen the pump. I'm going to pull it apart again this afternoon and see if I can find what I'm obviously missing. I got hold of the new style coupler, so will be ditching the centrifugal. Only thing I'm not sure of is readjusting the air after the coupler change. I can't get anyone out to adjust air for about a week (don't ask) and not sure how much it should be adjusted to get it close enough until it gets set correctly.
Air adjustment is not something to guess at. And not something thats easy to explain over the internet.
Air adjustment is not something to guess at. And not something thats easy to explain over the internet.
True, and I'm not arguing that at all, but I had to get it going well enough until someone could come with the right stuff to set it properly. So, I had a look at a friends boiler that is basically the same and set mine to match what his is set at and it seems to be running fine now that I ditched the old coupler. This thing has been problematic for a couple of years now and leaks internally when it cools off, so it's time to put it out of its misery anyway. Next month sometime I'm planning to replace it.
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