Dishwasher - repair or replace?

[Leo Enticknap]

Looks like the circulation pump is buggered.

Symptom was poor washing performance - the odd bit of crud baked onto plates at the end of the cycle, etc. Determined that the circulation arms were not rotating, by leaving a cup upright in the top rack and finding it empty at the end of a test cycle. Found no blockage in the filter or any hoses. Measured the resistance on the circulation pump motor - 723Ω, which says to me that it's dying or dead.

A new pump appears to be $350 for an OEM Bosch one, or $250 for a no name Chinese knockoff. Given that the dishwasher is nine years old and cost $700 new in 2016, and that similar replacements are going for around the same price at Home Depot, I'm reluctant to spend $250-350 to fix it. If the pump had been in the high two to low three figures it would have been a no brainer, but if I replace the circulation pump and then the control board or drain pump bites the dust next week (for example), I'll be underwater on the project.

Thoughts?

[Harold Hallikainen]

It is something that one part costs half the cost of the whole machine. We have a GE dishwasher where the controller keeps crashing. It appears to be a common problem on this model. We had the board replaced, and it lasted about a year before it started crashing again (resulting in none of the front panel buttons working). Someone discovered that if you keep power removed from the unit when not running it, it will start back up properly when the power is restored. A short power cycle does not restore it. So, my current workaround is putting a switched outlet strip under the sink. I turn it off when I unload the dishwasher, then turn it on when I want to run it. This really discourages me from buying a GE product again.

Repair of consumer products is quite an issue. We had a Cuisinart toaster oven. If you rotate the mode switch when it is running, the contacts arc and the switch fails. A replacement switch appears to be totally unavailable. Cuisinart replaced the unit after we sent them a photo of the unit with the power cord cut off. More for the land fill! Real waste!

Google says my most popular web page is one about fixing a countertop ice maker ( https://hallikainen.org/hzb-12b/ ). There is no service manual available. Customer support is only by text message. Based on the symptoms (I sent them a video), they determined the LED board was bad. That was not the problem, and they sent me the wrong board (it appears to be for a different model).

It's really discouraging that we throw so much stuff away. Leo, PERHAPS you could replace the existing one with the same model and keep the old one for replacement parts for the new one.

Good luck!

Harold

[Frank Cox]

Modern appliances are, apparently, crap.

The fellow who does appliance repairs in town here told me a story a while back about what happened after there was a big flood in Yorkton about a dozen years ago or so. Everyone who had their appliances in the basement (i.e. everyone) put in for new ones under their insurance policies even though their old appliances could probably have been repaired. And five or six years later on, those same people were wishing they had kept their old appliances because all of these new ones were breaking down left and right.

I think the lesson there is, if you have a good older appliance it's probably worth fixing it because you aren't going to get the same quality if you replace it.

[Marco Giustini]

When I have issues with my dishwasher I place my mobile in a sealed tupperware, widest camera possible, facing down on the higher basket.
Then in another tupperware I put my headtorch.

I then run the dishwasher and find out what's happening.

Last time I had issues, I noticed the pump was working but the arms were not spinning or badly. They were streaming water but not enough to make them spin - and water was coming out of both at the same time.

Turns out there is a contraption in the dishwasher to enable EITHER the top OR the bottom arm to receive water. On my inexpensive machine it's a simple disk with some holes in it which spins and basically lets water pass from one outlet or another.

SCR-20250928-jyat.jpg

I felt my arms had not been spinning ok for ages. What happened was that the microswitch which is telling the electronics "I'm in position, please remove power to the motor spinning the disk" had oxidised because of a small leak. With that not working fine, the disk would either keep spinning all the time or would stop in the wrong place resulting in the arms not receiving water or not receiving enough. I swapped the switch (in fact, I cleaned it) and the dishwasher works better than ever. The whole part was £60 and I would have probably recycled the whole machine if that was required (it's a basic model) but turned out the motor (24V) was spinning fine so I looked at the switch and bingo!

AC90C3F5-880D-4CDB-9514-C15336E4AD61_1_105_c.jpg

Some inexpensive machines are designed to fail 100%. I fixed mine way too many times. But every time it's a £10 fix and I cannot justify throwing it away for just that. Most importantly, despite the age and the crappiness, it works great...

[Leo Enticknap]

The maddening thing about this situation is that whoever designed this dishwasher clearly thought long and hard to make it as easy as possible to swap out the components that are likely to fail - the two pumps, the circulation valve shown in Marco's photos (presumably to enable the economy cycle whereby only the bottom rack receives water circulation), the intake and drain solenoid valves, detergent dispenser module, and the control board. Any of them can be replaced in an hour by a competent DIY-er, and the only tools needed are a T20 screwdriver and a pair of hose clamp pliers.

The problem in my case is simply the price of the part.

Leo, PERHAPS you could replace the existing one with the same model and keep the old one for replacement parts for the new one.

Thanks, Harold: that put an idea in my head. Maybe someone parted out one of these dishwashers after the failure of another part, and is offering a used but OK pump for a reasonable price? We do that with end-of-life projectors, after all. Sure enough...

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That is far more reasonable, and a risk I have no problem taking if it gives us another year or two out of this dishwasher.

But Harold's broader point is an important one. As someone who repairs machines for a living, I have no problem trying to fix my own. But if your average consumer who does not is faced with a bill for a $200-300 part plus the same again for labor, versus $700 to replace the entire machine, it's pretty obvious which option they're going to take, and an appliance that is perfectly good but for one component goes to the landfill. Add to that the education problem (many middle and high schools simply don't do shop class any more), and the waste caused by things being replaced when repair is perfectly viable becomes an order of magnitude worse.

[Stefan Scholz]

My dishwasher was bought 1996, and it still works. It has a true switch to turn it off, and relies on a mechanical, synchronous motor driving the program control.
The newer on in my flat relies on a digital controller, that utilizes an 8 pin IC to drive the low voltage controller circuit. The primary circuit is permanently under power, there's no main switch. Electrolytics fail after some 10 k hrs. So it is designed to fail, idle or not. I am using it with a switched power strip. But, another design is to have a fusible resistor in the input to limit inrush currents from the rectifier/ capacitor filter on the SM primary. That could eventually be damaged over time by inrush load.

I am not a fan of modern major appliances for home use.
I am running a fridge in my kitchen, AEG/ GEC dating to 1927 or 1929. No fault in the last nearly 100 years. Thick copper tubings, flexible. Only change so far, obviously in 1951 the D.C. motor was changed to an A.C. motor with high startup torque. I had to clean the centrifugal switch that decouples the startup capacitor, not more. And a new digital thermostat controller, using the same cutout diameter like the 1920s type.
Most people believe, it is rather ineffective, and I should buy a new "Energy Star A(++++) rating" unit. A guy I see on fb repairs the old grand dad appliances, and he has setups running an old GE 1930's fridge vs a modern Energy Star model with half the cubic inches of capacity. Over 2 weeks, both "ate" the same amount of electricity. All the gains theoretically possible in modern BLDC inverter design motors are wasted using thin insulation on these.

I like to keep these units, and often try to repair them. Often it's not a major part that is faulty. I actually think, pump motor can last very long. Mostly the gliding sintermetal bearings used in the split pole short circuit type used is the the item to give up first. It's not the winding, which is rather solid, and protected by impedance. Take it apart, clean the water path, look for the setup.
Another item to fail on modern electronic controls are the low profile relays they use to switch the load. Eventually reading 16 A/ 250 V, the contacts burn over time, giving bad contact long term. Then, the voltage to the motors drop, also look on these.

[Ryan Gallagher]

But Harold's broader point is an important one. As someone who repairs machines for a living, I have no problem trying to fix my own. But if your average consumer who does not is faced with a bill for a $200-300 part plus the same again for labor, versus $700 to replace the entire machine, it's pretty obvious which option they're going to take, and an appliance that is perfectly good but for one component goes to the landfill. Add to that the education problem (many middle and high schools simply don't do shop class any more), and the waste caused by things being replaced when repair is perfectly viable becomes an order of magnitude worse.

Yeah I was gonna mention if a 35mm/DCI cinema tech such as yourself (with tons of applicable experience) have hesitations attempting a repair due to the price points... forget the general public. Maybe as AI gets better at walking people through such things there is some hope more people will attempt it themselves? Other than that if someone on youtube has done the exact repair that is their best resource, provided the will to try.

[Marco Giustini]

presumably to enable the economy cycle whereby only the bottom rack receives water circulation

I don't know how dishwashers work in the US (but if memory serves you used to live on this end of the pond) but dishwashers constantly switch between upper and lower arms. I'd imagine it's to save on a bigger pump and also maybe for noise reasons? Just speculating. But all the dishwashers I've had behave like that. You can clearly hear one arm spinning and xx seconds later it switches to the other one.

Also yes, economy/delicate cycles might only use one or the other or "more" of one or the other.