Circulator Pump life

[Gary S]

What kind of pump life is typical for a circulator that runs 24/7 at least 5 monthes a year.

The reason I'm asking is the boiler temp is running like normal but it's takes forever for for the return to get up to temperature. In the past it only took 20 minutes or so. It seems to me like it's not moving water like it should.

Any advice would be great. Thanks

 

[mr.fixit]

I have never replaced any of my pumps going on 4th season.
I did have one apart because I thought the same thing you did but the impeller looked perfect.Not much else to go wrong other than leaking or the motor not turning.

I have found that if I close the balance valve to the danfoss valve down to far that the boiler temp stays up but no flow to the zones.
I think its because the thermostat in the danfoss doesn't see enough hot water flow to open enough(or long enough) to allow any flow from the zones.
Don't know if that makes sense but that's the best I can describe it.

 

[Pat53]

I would think you should get at least 5 years out of it. My old Taco 007 I had on My Aquatherm lasted 8 years before she seized up. It ran continuously 24/7 for almost 6 months a season. Most circulators have at least a 2 year warranty, some 3 years. But usually when they go they just quit, they don't just slow down.

Pat

 

[BoilerMan]

In my findings, a circ will work or not. It will either have a stuck shaft, burned out stator (copper coil) or the impeller will be eroded away. The last can be from cavatation due to, pump on return and not on supply where it should be, low system pressure, or an oversized pump for too small of a line (usually 1" pex for the underground). Silty or abrasive system water can also cause impeller erosion. When installed in the proper location or in a good enviroment I've seen pumps (mostly Taco 007s) last 20+ years. I'd expect a pump running 27/7 for 5 mo/year to last at least 10 years. Use isolator flanges and keep a spare on hand if it's a critical pump and remember a set of rubber gaskets! Also Taco has a replaceable cartridge which containes all the moving parts including the impeller which can be replaced in less than 10 min.

TS

 

[Bob Rohr]

In my findings, a circ will work or not. It will either have a stuck shaft, burned out stator (copper coil) or the impeller will be eroded away. The last can be from cavatation due to, pump on return and not on supply where it should be, low system pressure, or an oversized pump for too small of a line (usually 1" pex for the underground). Silty or abrasive system water can also cause impeller erosion. When installed in the proper location or in a good enviroment I've seen pumps (mostly Taco 007s) last 20+ years. I'd expect a pump running 27/7 for 5 mo/year to last at least 10 years. Use isolator flanges and keep a spare on hand if it's a critical pump and remember a set of rubber gaskets! Also Taco has a replaceable cartridge which containes all the moving parts including the impeller which can be replaced in less than 10 min.

TS

I think it depends on the life it lives. Water quality, stop and starts, and where it is running on it's pump curve. Like any motor it has an ideal operating range, put an amprobe on the leads and see what the current draw is. Excessive heat caused by the fluild or cavitation (water boiling in the volute) reduces the life. Most circs are rated for 225F, but the are happier at lower temperatures.

Grundfos now had a "tickler" installed to help start pumps that are in active for long periods and may stick. In many cases the capacitors fail, and a new one brings a failed pump back to life.

Also, some times pumps are left for dead and when the cool down the fire back up. I would guess 10 years or more for a properly sized and installer wet rotor circ. I've seen plenty of 20 year old ones. The way the motor technology has changed recently, I'm not sure we want a 20 year motor.

There is an association called EuroPump and every so many years they up the efficiency requirement, and older motors become obsolete. Look for the color bar on the side of the box to see where the pump falls. Similar to a gas milage rating on a car.

 

[MaineEnergySystems]

Taco 007, installed 1989 as boiler to boiler loop circ for connection between an oil / cordwood boiler set-up. Ran 24/7 each and every winter (late Oct. to mid April) from 1989 to 2011. Inspected last summer and when no wear was detected, it was reinstalled as one of 7 zone circs in my picture. 1 year out, it was the right decision so far.
Yup, I was impressed.

 

[mmudd]

Does starting/ stopping reduce pump life or extend life? All my pumps are controlled by aquastat/thermostats.

 

[BoilerMan]

I would say no, as there are no contacts as in a cap start motor, or a split phase motor. These are small capacitor run motors, not a whole lot to go wrong with them electrically speaking.

TS