Grundfos Water Pump

"Smithfarms Pure Kona" wrote

More information on the pump would help, Grundfos must make a dozen or more models of pumps. Is it a constant pressure pump?

Gary Quality Water Associates

Grundfos

Yes- a constant pressure pump, I think. I'll try and get more information but one of the benefits is the constant pressure. Apparently the pump goes on each time you turn on the water. With our current and soon to be old system, there is a notable difference in the pressure which also affects our Paloma water heater. aloha, Thunder

Farmers & Sellers of 100% Kona Coffee & other Great Stuff

"Smithfarms Pure Kona" wrote

I take it model is a Grundfos. All I know about them is how to spell the name and that they are a German company, I think. I sell Goulds and Sta-Rite. You can't go wrong with any of the three.

Gary Quality Water Associates

No pump needs an air tank, however, the captive air tank is a great option as it allows the pump not to have to cycle on and off for small, occasional uses.

"Rob Reali" wrote

ummmm not really. All pump/motor manufacturers want a minimum rest period of 60 seconds between starts for motors up to 1.5 hp; And over

1.5 hp it's 120 seconds. Water is basically unable to be compressed. So since the pump would start as soon as water was used, it would also build pressure all but instantly and shut off if the fixture being used can't handle the flow the system delivers to the fixture. That would cause an instant drop in the pressure and the pump would come on again to repeat this over and over while the pressure fluctuated drastically but, and here's the real problem, this would cause the system to experience and be damaged by water hammer. Probably until something broke and a pressure tank was installed, if only a 1.5 gallon tank that would act like a water hammer arrestor but also allow the pump to stay off for some time while water was used in small volumes. Also as important as water hammer problems is that without a pressure tank, the pump motor would likely as not burn out in a short period of time due to not being able to cool sufficiently between starts.

Gary Quality Water Associates

again

drastically

So Gary, in your opinion, is a $500+ grundfos worth buying? Or would you suggest something with a captive air tank. This is a big purchase and we have two neighbors saying it is the thing to buy but if it will burn out more quickly due to having to run for every water *turn on*, maybe it isn't the right thing. Oh well, our Paloma water heater died- after 20 years- last night, so we are off into Kailua Kona to buy a new Paloma. Hot showers tonight Always something! TIA aloha, Thunder...

Farmers & Sellers of 100% Kona Coffee & other Great Stuff