Dishwasher Water Recirculation Pumps
The dishwasher wash pump or recirculation pump is often referred to as the main dishwasher motor as it is the main pump that drives the water flow to the spray arms which then spray the dishes to clean them.
These pumps or motors come in various guises and, normally, none of them are cheap. They tend to be one of the most expensive spares in a dishwasher.
Classic Dishwasher Wash Pump
The classic type will be a simple single speed induction type motor coupled to a chunky impeller to drive the water up through the dishwasher.
An induction type motor is usually used because it's quieter and also more reliable as a general rule. These types of motor use a start capacitor to fire up, usually a small value capacitor such as a 4µF rating as the motors are not particularly heavy duty. This is good news as very often when the dishwasher wash motor runs slowly or you notice a weak spray or a reduction in cleaning performance, you will often find that the capacitor is faulty and not giving the motor enough of a kick to power it correctly. A very easy and cheap fix.
The wash impeller can also go faulty, either leaking or just break up as they are invariably made from a plastic, but where these are available as a spare they can be both expensive and very hard to fit. It is also vital to bear in mind that, should there be any damage to the shaft of the motor from it leaking such as pitting or scoring, that it will leak again. All that happens is that the pits or scores tear up the new seal in short order and you end up having to replace the whole motor unit anyway.
In recent years however this has become a bit of a moot point as most manufacturers will no longer supply an impeller kit as the motor production is usually outsourced and they are bought complete to reduce production costs. Does you no favours later on but it does help to reduce the retail pricing of a new dishwasher.
Magnetic Dishwasher Wash Pumps
When you mention magnetic dishwasher motors to a lot of dishwasher repair guys, they just cringe.
The idea was (and, the same applies to drain pumps as well) that using a magnetic pump cuts down on moving parts as there are no bearings, the unit is sealed and is therefore said never to leak and it's cheap. All good and no downsides on the face of it.
Only thing is, they're rubbish and break.
The most notorious is a dishwasher recirculation pump produced by a company called Askoll that was used in many dishwashers made by Whirlpool and sold under many different brands that Whirlpool supplied. These were pretty much all built in or integrated dishwashers and the failure rate on the Askoll pump seemed high and to add insult to injury it had the connections hoses bonded on to the impeller housing so they could not be changed. After a time Whirlpool issued a kit to that allowed the motor to be converted back to the classic type of dishwasher motor and, no problems with that after it's been changed.
For the moment most manufacturers seem to have dropped the notion of a magnetic dishwasher motor. Thankfully.
Wash And Drain Dishwasher Motor
There are a few dishwasher motors, like the Zanussi dishwasher motor in the photograph, that are dual function motors in that they perform both the pumping for the wash and, then when run in reverse also serve as a drain pump.
In most that we have seen so far these tend to be built around the same principals as a classic dishwasher motor but they do tend to be more expensive.
Ordering A New Dishwasher Wash Motor
Like all spare parts these are brand and model specific at best and, in many cases the serial, production or service numbers will be required to get the correct motor. Whatever you do, don't guess as you will probably get it wrong if you do. In some cases the production codes are not optional, they are required.
If you are not 100% sure of which motor to order then please ask as the few minutes that takes can save you hours or days of downtime while the error is corrected.
Getting To And Replacing A Dishwasher Motor
Like most working parts of a dishwasher the main motor is mounted underneath the wash tub, the wash tub being the tank where all your dishes go.
This often makes getting to the dishwasher motor a bit of a challenge, even for the professional dishwasher engineers in some cases and, especially in built in or integrated dishwashers as they must be removed from the kitchen housing to get access. And, even once you have access to the dishwasher getting to the wash pump can involve much gnashing of teeth and all too often cut hands as space in that area is usually pretty tight. So, please be careful and, as the area is so tight it is absolutely imperative that all power is removed from the dishwasher before you start any work or you might get an electric shock.
Once you get access most dishwasher motors are fairly easily changed and it is obvious how it is done but for specific advice please post a request in the forums. There are loads of video tutorials out there on this and a host of other things but they tend to be very generic and used as a tool to drive traffic to certain sites. The fact is that each make and often even model can be different and there is no way to explain blow-by-blow how to change every dishwasher motor out there. Therefore our usual caveat will apply, if you're reasonable good with most DIY chores and mechanically minded you can probably do this even if it can be a bit of hassle but, if you're not do yourself a huge favour and call in a professional dishwasher engineer to replace the motor for you.