LG pump motors fill with water
Hi
I have an LG washing machine which is about 13 years old now and not required any repairs until today. So I am very pleased with it on the whole.
It is a model WM-14331FD but I think my question would apply to most LG models.
Today the pump stopped working. I got the pump mechanism out and found there were 2 identical pumps, one for emptying the the machine and the other for spraying water back up to the top of the drum during some cycles. I applied power direct to the pumps on the bench and sure enough the emptying one was not working.
Rather than just buying a new one, I dismantled the pump to see how it had failed. The pumping chamber containing the impeller was clean. However, the motor chamber was full of thick smelly gunge. I cleaned it out and it worked again. I was surprised by the design of the motor since there had been little effort in the design to keep water out of the motor chamber, in fact I think it is designed to let water seep in. I opened the other pump and it also had a lot of filthy black gunge in the motor chamber, though not so much as to stop the pump rotating. You might be thinking how could an electric motor work when full of water, well it it is a brushless design with a permanent magnet rotor and external coil stator. The magnets in the rotor are indeed encapsulated in a waterproof plastic cylender.
So it is plain that what had happened is that dirty water had seeped into the motor chamber and over 13 years dirt and bacteria had concentrated around the rotor and jammed it.
My questions are:-
Am I correct in thinking the motor chamber in these pumps is supposed to fill with water (perhaps to aid cooling and lubrication)?
Is this a common design feature with other washing machine pumps?
If not, do the (non-existent) "seals" fail like this very frequently
Can anyone tell me a tried and tested routine for stopping dirt and bacteria from building up in the extraction/recirculation system.
Interesting points:
Although the LG is made in Korea, the pumps were made in Italy type Plaset 63096
Both the small service drain pipe and the recirculation pipe were also crammed with dirt and completely blocked.
Thanks for all your anticipated replies
Mike
Solution Summary
AI-generated from this discussion
This thread was marked as solved. Here's a summary of the problem and the fix, generated from the discussion below.
LG WM-14331FD drain pump stopped due to sludge contamination inside pump motor area
- The problem
- On an LG WM-14331FD washing machine, the drain pump stopped working. The owner removed both identical pumps and bench-tested them, confirming the drain/emptying pump was inoperative while the recirculation pump still ran. On dismantling, the impeller chamber was clean but the internal rotor/motor area contained thick black foul-smelling sludge. The service drain pipe and recirculation pipe were also heavily clogged with dirt.
- Likely cause
- Most strongly supported diagnosis is contamination build-up inside the pump’s internal rotor/bearing area causing the rotor to jam. One reply suggested that if water had passed behind the impeller it could indicate wear at the seal behind the impeller, but the owner reported there was no additional seal and believed this pump design allows water into that chamber.
- What fixed it
- The owner cleaned out the contaminated pump internals and re-used both pumps instead of replacing them. The accepted reply advised that water should not normally get behind the impeller unless the design allows it or a seal has worn, and noted pumps are usually replaced rather than rebuilt. No long-term preventative routine was confirmed in the discussion.
- Checks to try
- Removed both pumps from the machine
- Applied power directly to both pumps on the bench
- Confirmed the emptying pump was not working
- Dismantled the failed pump and found thick sludge in the internal motor/rotor area
- Found the other pump also contained black sludge but was still operational
- Found the service drain pipe and recirculation pipe were completely blocked with dirt
- Parts or tools mentioned
- Plaset 63096 pumps
- New pair of pumps quoted as about £90
Safety: Further diagnosis should be carried out by a suitably qualified appliance engineer.
2 Answers
Hello Mike. Yes most washing machine manufacturers just assemble washing machines from parts made by other companies these days. If you stripped down 10 different brands you'd find almost all parts look virtually identical and come from the same third party manufacturer.
I don't understand what you mean by motor chamber and pump chamber regarding pumps sorry. As far as I'm aware the impeller is attached to the rotor and sealed inside the pump chamber. Water runs into the pump and is forced out through the drain hose opening. Water should not seep past behind the pump impeller onto the rotor and bearing. If it has it's probably due to the seal behind the impeller letting water passed through wear. Water pumps are cheap and not well made these days.
If by any chance there isn't a seal behind / under the impeller then presumably they let water in as long as the bearing and rotor are sealed in. Not a very good design but it's lasted well at 13 years so it can't be that bad
Need Professional Help or Spare Parts?
Thanks for your reply Andy. I know it is hard to understand what I mean by motor chamber, at least it would be for me because I have never seen an electric pump designed like these before. I wish I had videoed the repair from start to finish because I couldn't find anything like it on youtube. All the youtubers just threw out the pumps, didn't dismantle them. Anyway after cleaning mine out I re-used them. The bearing is only plastic bush on steel spindle. And indeed this is all that would keep the water out, no additional seal. To describe the pumps a little more, there is an impeller chamber as expected, then there is a plastic disk (with the spindle passing through), on the other side a cylindrical chamber for the permanent magnet rotor, around that there is another chamber with nothing much in it (except crud!). The stator is a coil wound around and through the assembly. The stator does not come in contact with the water/crud inside the 2 motor chambers. Having considered it I am pretty sure the motor chambers are supposed to fill with water and this helps lubricate the bearing as well as cool the motor.Anyway if they fail again, which they probably will, I will video the repair. A new pair would be about £90. Apart from interest, the reasons I overhauled the pumps instead of replacing them are: speed to get washing again, risk of buying pumps that are not compatible (hassle) and cost.
Your Answer
Sign in to share your expertise and post an answer.
Related Questions
Hotpoint F7 E2 Fault
1 answer • 1 reply
My Bosch washing machine is stuck on 33 minutes remaining
1 answer • 1 reply
Bosch washing machine door lock accidentally triggered with the door open – how I reset it
0 answers • 2 replies
Cant identify the correct replacement carbon brushea
0 answers • 2 replies
LG washing machine making intermittent noise — video link included
1 answer • 4 replies