Smeg STX 45 Slimline fully integrated – Circulation pump :(

[mranderson69uk]

Hi,

I have a Smeg STX 45 Stainless Steel dishwasher as in subject.

I saw the previous post from the 44.1 SS owner, andy_b, and had the same issue except my capacitor had spilled it’s innards.

I noticed the dishwasher was quieter than usual and I could here the water being boiled or heated until it started bubbling. There was no swooshing of water in the wash cycle.

Well I checked out the pumps, the waste water pump worked fine but the the circulation pump wasn’t – sometimes I heard it trying to run but hum instead like a noisy transformer.

I removed the circulation pump an saw that the capacitor had bulged and spewed some of the grey metalised polypropylene.

I took a trip to Maplin and bought a replacement Motor Capacitor (an LCR 8uF part with the same voltage spec. – the only do one range http://www.maplin.co.uk/Search.aspx?cri … ce=15&SD=Y). I also checked LCR’s web site and they are designed for Motor Run / Start applications and the double terminals are actually 2 spades for each terminal of the capacitor – not two capacitor in one case …I checked with a Digital Capacitance Meter.

Well, a month down the line – approx. 5 washes – and the problems seems to have returned. I’ve not looked at the new capacitor yet but all the symptoms are there.

It was in mid wash cycle today and then I started to hear the water heating but no swooshing – soap had dispensed and there was a pool of soapy water.

So I’m now confused as to what would cause the capacitors to blow. The motor spun fine when I had it out last. There was nothing obstructing or evidence of anything damaging the impeller.

The only thing I can think of is that the centrifugal switch for the Motor Start Capacitor is not working properly – could it be keeping the capacitor in circuit feeding it with 240VAC all the time the d/washer is washing ? Can it be checked and fixed or replaced ?

The dishwasher was purchased in 2001 and not installed until 2003 due to not having the kitchen done. I’ve read about the “Capacitor Plague” problems that started around 1998/9 due to some incomplete stolen formula which resulted in capacitor not being stable, but this is a new capacitor – but as I said I’ve not actually checked the new one as the symptoms are the same.

Anyone who can help would be much appreciated.

Cheers
Adrian

[bobokines]

Re: Smeg STX 45 Slimline fully integrated – Circulation pump

Hello Adrian

The motor does not have a centrifugal switch, the capacitor is in circuit all the time the motor is running. Are you sure that the original capacitor was an 8 mF? I would have expected it to be 5mf. I can’t find a listing for the capacitor, only a complete motor. Someone else here will no doubt be able to verify the value for you.

You need to check the capacitor again to see if it has blown. Easy if you have a capacitance meter, not so easy without!

Capacitors can fail for no reason but it is unlikey that the new one has failed to be honest. If you have fitted the wrong value then you may have overheated and damaged the motor.

Just a thought… You mention that there are suds in your machine… That could be your problem. Dishwasher detergent does not foam up. It may be that your machine has been contaminated with a foaming chemical such as washing up liquid or overdose of rinse aid. The circ pump may be working but not circulating due to the bubbles…

Bob

[mranderson69uk]

Re: Smeg STX 45 Slimline fully integrated – Circulation pump

Hi Bob,

The original was a 6uF cap. from Italfarad. The new cap. is an LCR 8uF from Maplin and only fitted for a month.

When I said soapy suds, I meant the detergent tab had dispensed and when the heater heated the non-pumping detergent water it created a thin layer of very fine of froth – I guess it was almost boiling the water. The heater was switched off as part of the program or by thermostat but not before a bit of popping and crackling from the water. When the relay switched off the heater the popping noise stopped.

I have since run a rinse program and all seemed to function correctly. I got the swooshing sound for the whole program and the ‘beep beep’ at the end. So I guess the capacitor is still ok.

I’ll try another wash soon to see what happens.

Cheers
Adrian

[bobokines]

Re: Smeg STX 45 Slimline fully integrated – Circulation pump

You will goose your motor if you carry on using it!!!

An 8 mF capacitor will cause the motor to overheat. The thermal overload in the motor might cut in to protect it but it can still cause serious damage.

The current drawn through the capacitor rises to the square of the difference of the capacitor rating. (ie 1.8 times the normal current if you fit an 8 instead of a 6mF !!!)

You will be able to get the correct capacitor from this site. email spares@ukwhitegoods.co.uk

Bob

[NWAR]

Re: Smeg STX 45 Slimline fully integrated – Circulation pump

The capacitor for that machine is part number 811770337 – price & availability using the email address given above.

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