Washing Machine Drain Pumps

Washing Machine And Washer Dryer Drain Pump

We are only going to go into the electric drain pump in this article as it is the most commonly used type now and also one of the parts that can give the most issues.

Accessing the filter on a Blomberg washing machine you can see the drain pump impeller

The drain pump in your washing machine does exactly what it says on the tin. Its purpose is to drain the water from the machine and the principle is the same for a washing machine, dishwasher or washer dryer. In this article we will teach you about the various types of water drain pumps that are commonly used on a washing machine, how to diagnose a fault with them and how to replace them. As ever, if you are not confident, call in a professional repair company to do this work for you.

Like other tutorials in this section we urge you to read it fully before starting any repair work on your washing machine so that you understand what you are doing.

Each model of machine can vary in minor ways but the principals laid out in this article should allow you to diagnose and replace most washing machine pumps.

Top Reported Faults

When the drain pump is either blocked or faulty these are the top symptoms that will be reported:

• Water in washing machine won't drain
• Washing machine stopped full of water
• Washing machine won't spin
• Washing machine won't drain

About Washing Machine Drain Pumps

Almost without exception the drain pump will be mounted on the base, on the right hand side looking at the front on washing machines and washer driers. Of course it's pretty easy to track down the drain pump on most washers as the grey drain hose will always lead you straight to it. On machines where a filter is accessible, the pump will without fail, sit behind that and, in most cases, you will actually see the pump impeller when the filter assembly is removed as in the photographs above in part "3".

To the right is a typical Hotpoint drain pump, in this case manufactured by a company called Plaset and it replaces the older non-synchronous pump. Clicking the picture will take you to washing machine section in our online spare parts store.

Years ago washing machine drain pumps used to be different in design to what they are now, the general principle remains exactly the same, but the execution has changed for most washing machines and dishwashers. It is well worth noting, even if you read no more of this article and you need a new pump, that the quality of replacement pumps can be vast between original and replacement.

Pumps are one of the most common spares to fail. Every dishwasher and washing machine has one as well as condensor tumble dryers and, especially in the case of washing machines, they can be extremely common and so "cloned" or "copy" compatible spare parts often known as "pattern spares" can be widely available, usually from several different suppliers.

Before you attempt any repair, be safe, make sure that the power is totally off!

Of course before you do anything at all you have ensured that the filter is clear and that the sump hose hasn't got anything in it either? You do know that the drain is clear and that the drain hose isn't blocked?

Induction Washing Machine Drain Pumps

This used to be the most common way that a pump was made for either a dishwasher or washer but of late these have been in decline due to the rise of the magnetic type pumps that are now in extremely wide use.

We still see these pumps a fair bit, but the instances are less and even many induction pumps are directly replaced with a magnetic type pump instead of the same as the original pump.

The problem with induction pumps was that they leaked, as well as the usual pump faults like being noisy or not draining, from the centre seal of the main shaft on the pump behind the impeller. This was billed as one of the biggest reasons for the switch to magnetic type pumps. But, magnetic pumps are mass produced and tend to be cheaper in production even if that doesn't always translate to the price charged for a replacement drain pump.

Magnetic Or Synchronous Washing Machine Drain Pumps

Magnetic pumps first appeared from a pump manufacturer called Askoll, or at least those were the first that I came across ten years or so ago at least. They were quickly followed by the other leading pump manufacturers like Plaset, Hanning and Coprecci with their own versions of the magnetic type pumps.

The up sides of these are that they are cheap, they don't leak (generally) and they are self-reversing, all of which are less hassle for the manufacturers as well as representing a decent cost saving.

These pumps do still go faulty though, a lot. Whilst they do have some distinct advantages over the traditional induction pump they do seem to be easier to jam up. They don't seem as powerful as the older pumps either, but I'm sure that the flow rates will be pretty much the same.

A drain pump made by Plaset to fit a Servis washing machine showing the magnetic armature

These pumps can produce a "screeching noise" from the washing machine (or dishwasher) though as the magnetic inner which is spun by the coil on the outside casing by the magnetic field (hence magnetic pump) is lubricated by the water. This is a problem, as we've found in the field, where there is sand or suchlike in the water or clothing as the tiny particles get between the magnet and the plastic pump casing giving the most awful howl when the pump is running.

Copy Washing Machine Drain Pumps

Two pumps, both from Plaset with very different connections on them to fit Hotpoint and Servis

As I said earlier, copies of pumps are extremely commonplace in the industry and some are good, some are bad and some are just downright awful. It is not unusual to get situations such as shown above, on two pumps for the same machine.

Most engineers won't use the bad, cheap copies and with very good reason. If we have to guarantee our work, whether it's on contract or a direct call that the customer is paying for, the last thing we want to do is fit a part that we know has a fair chance of failing inside that warranty. So we tend to fit an OEM equivalent or, if there's none available, we'd usually fit the genuine OEM part as opposed to something that we consider to be rubbish.

It makes sense as, if the part fails, it costs us a lot of money to put right. The equation runs that for one recall we have to complete a minimum of three calls to make that up, so you can see it's only in our best interests, as well as our customers, that we don't get failures.

Of course for a DIY repair the original, or a direct equivalent is the best bet as these are the easiest to fit yourself if that's what you're doing. The problem here is that some of the copy parts are a bit harder than that.

You will find that some replacement pumps are just a hassle to fit. Mounting points aren't the same, terminals are at different angles or don't have the proper connectors, pump housings are mounted at the wrong angle and so on. This is fine if you know what you're about or you are used to having to alter things to make good, but it can be a bit of a bodge job at times. This is another reason that we use good replacement parts, we don't need the hassle quite honestly to save a couple of pounds.

One of the most important things to watch out for when it comes to magnetic drain pumps, is that the rating of the replacement is adequate. Even though, for example, many Askoll pumps look identical, the ratings change depending on the machine or purpose of the pump. One of the best examples of this is the recirculation pumps on Zanussi Jetsystem machines as, since they run much longer than a normal pump they are higher rated to deal with the extended running times. Fitting the incorrect or wrongly rated pump will lead to early failure or, in extreme cases, the pump burning out.

Is A Washing Machine Drain Pump Cheap And Easy To Replace?

Some are, some aren't.

Whilst an appliance engineer may well walk in and replace a pump inside ten minutes that is only down to his experience and knowledge of the machines. Where he not to know what he was about he'd very likely take an awful lot longer and make mistakes, or at least not be aware of the quickest way to replace the part or even what part was the problem. Most repairers have a kind of sixth sense when it comes to a broken washing machine, they just "know" what's wrong or have a very good idea before they even look at the machine.

To replace a pump the cost can vary, mostly due to the varying prices of the spares, but expect to pay between £35 and £50 in labour, which is fair. Remember the chap has to travel to you as well as make a living so the repairer isn't actually making a fortune at that, just think how much a plumber would cost.

For the part only you're looking at anything between about £15 and £80, seriously they do vary that much in price.

It is worth noting that some manufacturers, like Miele, really take the Mickey with parts prices, like £150 for a drain pump!

Washing Machine Drain Pump Electrical Connections

In almost all washing machine and washer dryer drain pumps there are only two connections, a live and a neutral.

Most washing machines are live switched so there should always be a neutral present in most but what you might find and, this is a top tip, on some machines (especially Italian for some reason) the neutral feed for the water valve is routed through the drain pump. You may wonder why but it makes perfect sense, if the drain pump on the washing machine goes open circuit it chops the power to the water valve so that the washing machine cannot fill. Pretty sensible really as there's no point in filling a washing machine with water when you can't drain it back out again.

For the most part though, there's nothing even remotely complex about the wiring of a drain pump.

But what we have seen is a huge rise in special keyed connection blocks to connect the drain pump and odd positions for the connections. This appears to be an attempt to stop or, make difficult, the production of cheaper copy replacement drain pumps.

Now we as repair engineers can get around this problem easily by simply chopping the original connection block off, fitting a couple of standard spade terminals and fitting a cheaper drain pump but, if you are not comfortable doing this then we would suggest either calling in a professional or buying the genuine drain pump only as a spare part.

Buying A Washing Machine Drain Pump

If you ask where to buy we would naturally say, from us of course, but I can offer you some reasons why.

For a start we know what we're doing and what we're looking at, we also know all the alternatives which can quite often save you a fair bit of money. We also, importantly, know what not to fit or attempt to fit and what parts are not worth the hassle. UK Whitegoods helps people not only find the right parts but also helps you not to choose the wrong one.

We also just happen to be very competitive on price, often the cheapest in a like-for-like comparison.

Common Washing Machine Drain Pump Failures

Common pump failures and some of the popular reported faults are below:

Noisy on draining: Pump bearings faulty, something stuck in the pump

Screeching noise on drain: Something stuck in the pump, sand/grit in the magnetic types (this can also be reported as a screeching noise on spin as the drain pump runs whilst the washer is spinning)

Not draining: Pump blocked or faulty