DIY Doctor UK DIY Forums

We have a 17year old Miele Prestige Plus washing machine and it knocks out the RCD sometimes in the niddle of the wwash cycle and sometimes after it completes the wash cycle, There are times it does not bloow the fuse at all.
Is the problem something worth repairing? The machine is on its own small Consumer unit shared with fridge freezer.
Any views

An RCD monitors the in and out current and assumes if they don't match, the current is going to earth, There is always some loss, as we use AC, so there is some inductive and capacitive linking so typically we use a 30 mA RCD.

We should when installing monitor the background leakage which should not exceed 30%, but in the early days we had little option, the early consumer units were not designed to use a RCBO (MCB and RCD combined) so we had all on one or two RCDs.

The result is it can be hard to be sure what is causing an RCD to trip, with neutral to earth faults the load has a big effect, so a fault with a bit of damp toast in a toaster, can trip the RCD when the kettle is used, so since the washing machine is a high load, it could cause a trip when the real fault is something else plugged in.

So step one, ensure nothing else plugged in.

Any mineral insulated heating element will draw in moisture if the seal is damaged, So ovens, washing machines, resistive tumble driers, frost free freezers, all have these elements, the test is to use 500 volts DC to measure the resistance, this uses a special tester, the other method is to measure the AC leakage with a clamp on ammeter, the problem for the DIY man, is likely they have neither, and it is a lot of work and expense to swap a heating element to see if that cures the problem.

Since I have both, for me, it is easy, they are not super expensive, around £35 but still a lot of money for a one-off use, so do you know anyone with one you can borrow?

You need the services of a person who works with your brand of washing machine all day, call Miele and ask them how much call out is and what is or is not covered. It will not be the heating element as it only comes on in "heat pause" and it would happen every time, which it does not, call Miele

Thanks for the info.
Miele want £190 for an engineer and any repaire would be £290. A bit steep.
Is it possible that the RCD in the two way consumer unit is tired! The consumer uunit is a two cable arrangemt One slot is 30 amp the othe 6amp for the liight. the only items is on the 30amp fuse are a Tumble dryer [never used when the washing macine is on] It is strange the way the fuse behaves sometime it does't trip other timesit trips either in mid cycle and sometimes after cycle ends.
Since the Machine is 17 years old we are considering a new on.
Many thanks,

The element in most domestic appliances is switched on with the line only, so even when not on, it can still cause a neutral to earth fault. With a mineral insulated heating element, the heat can move the moisture, so it can appear as if some random fault.

I have in the past, when I had no test gear, disconnected the heater to test if that was the problem, but today I have meters which make it easy.

But at 17 years old, is any repair, throwing good money after bad? I would clip my meter to earth and neutral (not line, as this is likely switched off) and press the button, and any reading under 1MΩ would show to me the washer is faulty. A 2-minute job to test, but the meter cost me £35, so I would say, off to the pub, buy an electrician a pint, and ask if he can do a quick test with his meter. I would say hire, but meters should be calibrated, and that means as cheap to buy as hire.

billobach181 wrote: ↑

Thu Aug 01, 2024 9:13 pm

Thanks for the info.
Miele want £190 for an engineer and any repaire would be £290. A bit steep.
Is it possible that the RCD in the two way consumer unit is tired! The consumer uunit is a two cable arrangemt One slot is 30 amp the othe 6amp for the liight. the only items is on the 30amp fuse are a Tumble dryer [never used when the washing macine is on] It is strange the way the fuse behaves sometime it does't trip other timesit trips either in mid cycle and sometimes after cycle ends.
Since the Machine is 17 years old we are considering a new on.
Many thanks,

think with that price to get someone out to it, you may as well buy a new one like you said for that price. With it being 17 years old maybe its just had its time.

@ch3shirecat4, if it was a el cheapo brand I would agree with you, but he did say Miele.

Have you seen the price of the average Miele, (£1,149.00) They are also expected to last for at least 20 years