Trips in hot cycle, but heat element tests ok?

[Alan-Murphy]

Bosch washing machine started  tripping circuit breaker during normal hot wash. It drains ok, spins ok, does a cold wash ok,  but part way into a hot cycle it trips trip switch and water never heats up, so I assumed it was a dodgy heating element.

I opened it up, removed heating element and multimeter reads 26 ohms across its live/neutral pins. My calculation is (220 x 220v) / 2000W = 24.2 ohms, so it's pretty close. No continuity between live/neutral and earth. Thermostat/temp probe is reading around 5 ohms, with multimeter dial at 20k, and falls with rising temp if I warm it up, so seems to be working too. 

 

If it's not the heating element or temp. sensor what else could it be?

 

Thanks in advance!

[Whitegoodshelp (Andy)]

Hello Alan. Unfortunately if you don't have an insulation test meter you can't troubleshoot a fusing or tripping electrics fault. A continuity test meter would detect a direct short to earth. But an appliance can trip with modern fuseboards with a relativley small leakage to earth that wouldn't be picked up with a continuity meter. The insulation test meter used by repair engineers puts 500 volts (DC) through the part to test for insulation leaks. It's explained in my article here - Washing Machine Tripping or Fusing Electrics

[Alan-Murphy]

Thanks Andy - so given the facts (it drains ok, spins ok, does a cold wash + spin cycle ok,  but part way into a hot cycle it trips tripswitch and water never heats up), is it reasonable to assume the problem is likely to be the heating element? Seems the most logical, and a simple enough replacement to try, right? 

[Whitegoodshelp (Andy)]

The heating element is one of the most common causes of tripping the electrics. Especially if it only trips part way through the wash cycle. You can't be sure, but if forced to guess it's the most likely explanation.

[Alan-Murphy]

One more update - I had incomplete info yesterday. More details: 

The machine does not finish a cold wash cycle, but ends without completing the spin/drain, and the lights indicate cycle has ended (no blinking/error). You can then manually set a spin cycle, which runs & drains ok, but it does not complete during the normal cold wash cycle. And the hot wash cycle is the one that trips the electrics.

What would that suggest - a dodgy circuit board? As well as a dodgy heating element? Seems like two different faults going on...

Is there a "master reset" for the Bosch WFL2060GB? I found one on-line, but it includes press/hold the spin button, but i don't have a spin button, just a spin dial! Maybe they meant Rinse Plus button? Another said to open/close door quickly 6 times, didn't seem to do anything (or else some-one's having a laugh!!).    

 

[Whitegoodshelp (Andy)]

There shouldn't normally be a need to reset anything. Once the fault is cleared it should work as normal. Aye the open and shut the door 6 times sounds very much like a wind-up

Low insulation faults can cause strange faults and behaviour on some washing machines. However, it's not possible to rule out more than one fault. If it doesn't complete the cold cycle I would assume it at least drains the water away even if it doesn't spin. The only thing you can do is get an engineer or gamble fitting a heating element.