Warn impeller on 9430DC

ReefHog · Feb 10, 2021

@rvitko Hey Rodger, The pump on my 9430DC won’t restart when I pause it for cleaning. The controller flashes off and on. I cleaned the pump and put it back in service and it worked fine until I paused it again. Now I’ve been just leaving it run while I clean the collection cup. The impeller looks warn at the bottom quarter. See attached. Is this under warranty? I purchased it on 2/08/2019.

rvitko · Feb 11, 2021

This type of wear would be caused by some foreign object in the pump and would generally not be a warranty issue. However, it should not cause any issues except possibly some added motor noise. Is their any raised area or blemish in the motor? Is the bearing down in the motor firmly seated in the motor?

ReefHog · Feb 11, 2021

rvitko said:
This type of wear would be caused by some foreign object in the pump and would generally not be a warranty issue. However, it should not cause any issues except possibly some added motor noise.

This just happened a week or so ago. I paused the skimmer for cup maintenance and when I turned it back on, it didn't start and the blue light was flashing. So I pulled the whole skimmer out and gave it a good cleaning. The impeller looked like that and actually had a sort of peeling at the bottom that was hanging over the edge of the magnet about a 2 mm. I was able to rip the overhanging "skin" part off. I didn't notice anything abnormal with the pump but I didn't imspect it with a flashlight or magnifing glass. There was some sticky black stuff on the outside of the brown bushing on the magnet side. Could this be plastic melted away from inside of the impeller socket? I was able to just rub it off with my thumb. There was nothing on the magnet part of the impeller. It is just worn toward the bottom. Now what is happening is that when remove the impeller and bearing and then re-seat it, it starts and runs fine. But as soon as I stop it, I have to re-seat the bearing and impeller again. When I remove the impeller, the magnet side bearing comes out with it. In the past I believe the magnet side bearing would just stay in it's socket and the impeller would come out with just the shaft. I can't imagine what type of foreign object could get in the area between the magnet and the socket. Maybe some hardened calcium flaking or something. It was suggested that I lightly sand the rough part of the magnet to smooth it out. Seems like that could help with it binding/locking up but not sure how that would affect the proper tolerance. Maybe not at all. And possibly adding a layer of pipe tape to the outside of the bearing so it fits more snugly in the socket. For now I'm just going to leave it running during cup maintenance and check it next week to see if the conditions inside the pump have changed. If I have to replace the impeller and or bearings, it's not the end of the world. A new pump would really suck. I'm sure they're quite expensive.

rvitko · Feb 11, 2021

That can be the case, it is not the end of the world though. What would cause this is that the impeller seized to the bushing and spun it, calcium had built up enough to lock the parts up. There is an oversize repair bushing for these cases. It can also be that the issue is just the bushing, if you take the other bushing they are identical, if the wear is minor and more to the bushing, you may just have to swap them. I would be hesitant to sand the impeller much, I could see working away some of the roughness with a quick pass, but we don't want to breach the coating or the magnet will rust and swell.

ReefHog · Feb 11, 2021

rvitko said:
That can be the case, it is not the end of the world though. What would cause this is that the impeller seized to the bushing and spun it, calcium had built up enough to lock the parts up. There is an oversize repair bushing for these cases. It can also be that the issue is just the bushing, if you take the other bushing they are identical, if the wear is minor and more to the bushing, you may just have to swap them. I would be hesitant to sand the impeller much, I could see working away some of the roughness with a quick pass, but we don't want to breach the coating or the magnet will rust and swell.

The two bearings look identical to the eye. If anything, I would think there would be a slight (micrometer) wear on the pump housing socket where the bearing possible spun. Where would I get a bushing repair/replacement kit and/or an impeller should that become necessary? I would only lightly sand the rough stuff that is not providing any protective coating anyway. I rebuild large comercial pumps all the time for work and have even sanded some flame sensors on furnaces with dollar bills so as not to comprimise the integrity of the sensor when they get fouled, so I'm skilled in that respect.