Utica MAC-150 noise

john p_2

At a friend's house who has a Utica MAC-150 and has a squealing noise when calling for domestic hot water.  The squealing disappears once the domestic hot water pump is unplugged. Does he need to change out the complete pump or is there a part inside that can be replaced? Also, it appears it is taking a bit longer to get the hot water at the fixture than it used to. 

EdTheHeaterMan

Yea, good diagnosis unplug the pump and the noise stops. You found the source of the noise! Now you can replace the cartridge only by removing these 4 bolts.

john p_2

Ed, thank you. The system is not very old and in a beach house. What would/could cause it to go?

EdTheHeaterMan

That screw cap in the center of the pump is there in case that pump gets stuck (from lack of use). Try removing that screw cap and see if pushing on the cartridge that is directly behind that screw cap while the pump is operating, will free up any build up on the inner'ds of the pump and make the noise go away. If that does not help then you will need to replace the cartridge (inner'ds). As far as the cause, I can only speculate that there is some debris inside the pump that is rubbing against the impeller. Just taking it apart and cleaning it might be all that is necessary.

john p_2

Thanks, for sure I will try that. Having a hard time finding the correct cartridge to get despite seeing the pump part # on the pump. See plenty others but not for this pump.

Ironman

That pump is basically the same as a ups15-58. Lots of luck finding a cartridge, and if you do, it will be near the cost of the entire pump.

I’d  just bolt a 15-58 back in at the four Allen screws that Ed showed.

Those pumps rarely go bad and squeal unless they’re run dry from lack of water or the boiler having insufficient pressure and being air bound.

I’d look for the cause of the failure.

EBEBRATT-Ed

If there is any black pipe in the system? Has it had glycol in the system that could be contaminated?

Seeing that it is a beach house