help with grundfos pump

curiousity kills

Today I had a grundfos pump on a boiler fail to work after I drained the boiler to perform a repair.The pump had voltage going to it but would not pump water thru.This is the second time this has happended with this type of pump.The first time I had all the ball valves on the zones off with the pump running and I thought that was the cause but now it happened again and I did not turn the pump on until all zones were purged and valves open and the pump would not work.Is there something with this pump I am supposed to know.I am more familier with the taco.Thanks

Jack, CVMS

Grundfos pump

Which model pump is it? UP15-42F, UPS15-42F, UPS15-58FC, etc.?

curiousity kills

???

Im sorry I wish I took the model down.It had three settings if that helps at all.All three would not pump.It just seems wierd how this has happened twice to me with this same pump.

hr

Carefully

lossen the four allen screws, a turn or two, around the pump motor. Then lightly tap the motor to loosen the seal. Becareful, if the pump has been cavatating (running without pumping water) you may have steam when you loosen it! As soon as you get a squirt of water tighten the bolts.

I'd be willing to bet you have an airlocked pump. Easy to do with those intergral checks IF in fact you have a 3 speed 15-58.

I sometimes loosen the pump like this, on a newly replaced installation, and just crack the supply side iso valve to assure the pump volute has water in it before plugging 'er in.

You can accomplish the same thing at the flange bolts, if that is easier for you. Loosen the bolts on the discharge side. Becareful not to loosen enough to dislocate the ring gasket

hot rod

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Weezbo

if there is a big ss \"screw\" head on the pump....

then take it out completely ,with the power offpush the screw driver into the opening and give it a twist when it hits the groove. turn the power back on,if water comes out,put the screw back in..slowly..till it is no longer leaking...if not,put the screwdriver in the slot and if you cannot hear sound of the motor driving the pump, it means its locked up.. turn the power back off valve the pump remove the motor and turn it by hand..if the impeller is warped its by the number from there.if it turned bump it if it dont go maybe you have accidently worked a wire loose to the capacitor.

curiousity kills

Thanks for the replies.There was a large slot head screw on the end I removed it but did not see anything.The pump was making noise but not pumping.I believe the first time this happened to me it was because the pump ran without moving water.When I saw this pump and remembered what happened last time on the same type I disconnected the tt on the triple aquastat and did not reconnect it until the system was purged and all valves opened but I could not get it to pump.I ended up replacing the pump since by this time it was 8 pm and will not be going back but trying to prevent this in the future.

curiousity kills

Hot rod the thing that bugs me is the water feed enters just above the pump and has to go thru the pump then the boiler then the suppley and then return.There could have been air in the pump but I couldnt see how it would not flush out.