15-42 vs. 15-58

ScottMP

having problems with the speed switch on the Grundfos ??

I've had several where the circ is stick and by switching it to another speed it fires right up !!!

It’s been a real nuisance


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Timco

How does the 15-42 fixed speed compare to the 15-58 3 speed in gpm? (does the 15-42 = speed 2 on the 15-58 for example?)

Tim

Ron Gillen

Pump Curves

Sorry I can't fiqure out how to post the curves but you are right. The 15-42 runs from 15' to 17 gpm. the 15-58 Speed 1: 14' to 11 gpm, Speed 2: 17' to 15 gpm, Speed 3: 19' to 18 gpm. At Speed 2 you get 6 gpm against 10 feet with the 15-58 and 6 gpm against 11 feet with the 15-42. Hope that helps.

Brad White_202

As a point of reference

the "42" and "58" numbers refer to the maximum head in decimeters. In other words, 4.2 and 5.8 meters respectively.

But for the GPM, use the curves of course.

DaveB

We've had a couple in the last month. Seems like you have to get the cover on just right, even then the detents are not apparent. Maybe a bad run of switches?

kpc_44

I actually liked...

the older cover they had. The one where you needed a slotted screwdriver to switch it...