pump hums but doesnt start

junklar

New member
Jul 12, 2012
1
0
#1
Hello all,

I have a AO SMITH UST1102 1hp pump. The pump hums but won't start. If I hit it with a hammer, it starts and will continue to run all day until it shuts off by a timer. When it shuts off it won't run again unless I hit it with a hammer.

What can be the problem?
How can I fix this?
 

jblizzle

Mod Squad
LifeTime Supporter
TFP Expert
May 19, 2010
41,193
4
Tucson, AZ
#2
Sounds like the start capacitor(s) could be bad.

I am not very clear on how to test them though ...

Or maybe the centrifugal switch is sticking?