I have a bell and gossett booster pump that turn on for one minute then shuts down

one has cast iron body, one has a bronze body. looks like you kin ifin ya want to......

if pump it self is good look for a replacement motor can do search online or search for companies such as grainger --pump supply --plumbing supply companies online such as national https://www.nationalpumpsupply.com/?gclid=EAIaIQobChMImanlsNGl9gIVCgmGCh0vjg_xEAAYASAAEgIaiPD_BwE also check coupler ---this way for now dont have to drain system the companies should be able to cross reference a motor

I'm not sure which pump fails after 15 minutes. Is it the main pump or the booster pump? The main pump works fine but when the booster pump is activated, one of them fails. What happens if you leave the main pump on and only activate the booster pump? Will the booster pump run indefinitely as well? They both share the same supply line. What have you checked so far? How old are both pumps?Do you pumps sound normal? Do the pump motors get abnormally hot? Any recent repairs or new symptoms? Is there a shut off valve on the supply line that has been turned/moved? Please write back with more information.

the pump itself doesn't make any hot water it merely circulates it around your house to the sink outlets , this pump has a unique feature as it auto senses the temp of water and starts itself when it dips low , if you don't get any hot water even if you wait 4 it a moment then id have a service tech ck your water heating equipment , as it seems its not working

Sounds like it is not getting oil. The bearing oil fill cover can be removed by lifting outer plate with a screwdriver. Ck that the wicks are covered with oil , if not oil them. Put 3 drops in motor oil fill tubes. If still squealing, replace.

I am going to assume the circulator pump is on a hot water circulation loop. Turning the water back on could have stirred up the sediment that has collected in the bottom of the water heater. This could clog up and possibly ruin the impeller. Running for an extended period without circulating water can overheat and damage the pump also. It is a good idea to hook a hose to the water heater drain and flush out the sediment periodically. Hope this helps.

Replace the bearings...they are the noisy part

The following websites are parts suppliers for Bell and Gossett pumps and should be able to tell you the exact instructions especially if you buy the impeller from them:

www.statesupply.com/pumps-for-heating/bell-and-gossett/series-pl-pumps-and-...

www.nationalpumpandsupply.com/bell-gossett-pl-pump-pl-55-2-5-hp-motor-1bl03

You would be better off with a brand that has better representation than Grundfos. Several of our commercial customers change to brands such as Armstrong or Bell & Gossett the first chance they get because Grudfos is less reliable and getting parts or service on them much harder.