bell gosset circ pump not working

The boiler doesn't know if there is even a pump there. If the pump failed then the boiler fired and shut down when it hit the high limit set point. You need good water flow thru the boiler to keep it firing. It is probably a cast iron boiler and is hot and will take quite a while to cool down to where the aquastat will fire it again.

Now you might have flow-check valves which prevent gravity flow of hot water during the off cycle. There may be a lever that you can open/unscrew to allow gravity flow to your radiation. Then the boiler would maybe fire, but not very long.

If you try the lever it may be stuck, wiggle back & forth carefully, a little lube oil may help....they do break off.

A cause of B& G broken couplers can be bad/sagging motor mounts. This overworks the universal joint function of the coupler. If the motor mount is egg shaped at all then you should replace both of them in addition to the coupler.
The mounts are about 2 1/2" in diameter on each end of the motor. All 3 of these parts are common and not difficult to change. Do not over oil. If you buy the B & G oiler tube you get the exact instructions with it. One oiling per year should be all you need.
If you can't find the manual flow/check by-pass send pictures.

Abracadabra said:

joeant18 said:

why does the burner not turn on when a circ pump goes bad, B&G coupling bad , does the aquastat not allow this , thanks

There's probably a flow switch.

And if there isn't, its off on high limit.

If it does have a B&G Series 100 3 piece circulator, the install probably dates back to the last 1/4 or the last century. Or before. Few flow switches back then.