9410DC Noise / squealing pump

lancesmith1 · 11/12/2017, 06:46 AM

Roger - I am having a problem with noise from a new 9410DC. I put the skimmer in the sump this week (brand new). It started making the squealing / grinding noise after just a few minutes, If i unplugged it and plugged it back in it would run ok for a couple of hours then start back with the noise. Now, it is non stop to the point where it sounds like it is about to seize up. I checked the bushings as you have prescribed and they are fine. I have contacted MD to exchange the pump. But, i thought I would check back and see if there was anything else you would suggest. I think I may have a defective pump.

rvitko · 11/13/2017, 11:20 AM

Generally this will be a bushing that is not seated in the pump sockets, they should not be loose or come out but firmly seated down in the socket in the motor and impeller cover, they do sometimes come loose in shipping. If that is not it, another possibility would be not seated deeply enough or a wrong intake housing, the DC model has a slight change to the intake and if the factory mistakenly fitted an AC housing it will get too much air and cavitate.

lancesmith1 · 11/13/2017, 06:32 PM

thanks for the reply. I will double check but everything looks ok to me as far as being seated. Do you have an ideal depth to run this skimmer? Could it be the pump heating up with only a 3rd or so of it submerged at 6.5 inches?

rvitko · 11/14/2017, 09:10 AM

6.5" is ideal, the DC model is far more adaptable to water level but that should be nearly perfect. The bottom bushing needs to be pushed in with a dowel or something similar, you cannot push it in with the drive unit as it will just ride up the shaft and not push in. This is the number one cause of noise on any of these pumps, this bushing can come loose in shipping. Keep me posted, I will exchange the pump if this continues.

11/12/2017, 06:46 AM	#1
lancesmith1 Registered Member Join Date: Mar 2005 Location: chattanooga, tn Posts: 54	9410DC Noise / squealing pump Roger - I am having a problem with noise from a new 9410DC. I put the skimmer in the sump this week (brand new). It started making the squealing / grinding noise after just a few minutes, If i unplugged it and plugged it back in it would run ok for a couple of hours then start back with the noise. Now, it is non stop to the point where it sounds like it is about to seize up. I checked the bushings as you have prescribed and they are fine. I have contacted MD to exchange the pump. But, i thought I would check back and see if there was anything else you would suggest. I think I may have a defective pump.

11/13/2017, 11:20 AM	#2
rvitko RC Sponsor Join Date: Apr 2000 Location: Austin Texas USA Posts: 35,785	Generally this will be a bushing that is not seated in the pump sockets, they should not be loose or come out but firmly seated down in the socket in the motor and impeller cover, they do sometimes come loose in shipping. If that is not it, another possibility would be not seated deeply enough or a wrong intake housing, the DC model has a slight change to the intake and if the factory mistakenly fitted an AC housing it will get too much air and cavitate. __________________ Roger Vitko Tunze USA "He's for every one of us, stands for every one of us, he'll save every man, woman and child in a mighty Flash!" Current Tank Info: 210 gallon planted tank with Altum Angelfish

11/14/2017, 09:10 AM	#4
rvitko RC Sponsor Join Date: Apr 2000 Location: Austin Texas USA Posts: 35,785	6.5" is ideal, the DC model is far more adaptable to water level but that should be nearly perfect. The bottom bushing needs to be pushed in with a dowel or something similar, you cannot push it in with the drive unit as it will just ride up the shaft and not push in. This is the number one cause of noise on any of these pumps, this bushing can come loose in shipping. Keep me posted, I will exchange the pump if this continues. __________________ Roger Vitko Tunze USA "He's for every one of us, stands for every one of us, he'll save every man, woman and child in a mighty Flash!" Current Tank Info: 210 gallon planted tank with Altum Angelfish

11/13/2017, 06:32 PM	#3
lancesmith1 Registered Member Join Date: Mar 2005 Location: chattanooga, tn Posts: 54	thanks for the reply. I will double check but everything looks ok to me as far as being seated. Do you have an ideal depth to run this skimmer? Could it be the pump heating up with only a 3rd or so of it submerged at 6.5 inches?