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My Bosch dishwasher has stopped working properly. It doesn’t heat the water and the cycle won’t finish.
It is an SHV55M03/GB, approx 7 years old.
Having read the posts on here I removed the pcb expecting to find an overheating relay.
However, the relay connections look fine but I did find this-
Pcb casing-
Back of board-
Front of board-
I’m no electrical expert but I don’t think it should look like that.
Would that chip cause the faults I have?
Is it repairable or do I need a new board?
Any advice gratefully received,
MikeRe: Bosch Dishwasher not heating up and cycle never stops
I would check the resistance of the heater element (remove rh side panel and heater box is bottom right)Should be 25-30ohms
If oc then thats your problem-as always plug out before going in.Re: Bosch Dishwasher not heating up and cycle never stops
Ok, I checked the resistance of the heating element. It came out at 23 ohms. Is that within limits? I guess they go open circuit when they fail. Is it pointing to the circuit board again?
Many thanks for your advice,
MikeRe: Bosch Dishwasher not heating up and cycle never stops
bikemike wrote:Is it pointing to the circuit board again?
I’m pretty certain that that is the case although your photo is rather centred on the overheated chip. I would prefer a full shot of the board but more appropriately perhaps, where that chip circuit is directed? (what component could be causing the overheat?)
Re: Bosch Dishwasher not heating up and cycle never stops
Will do, just got to dig the camera out again!
Thanks,
MikeRe: Bosch Dishwasher not heating up and cycle never stops
Right, here are a couple of photos of the whole board.
Back of board-
Front of board- the overheated chip is the one below the main ecu.
Many thanks for looking,
MikeEdit- for some strange reason the edge of my photos seems to have been cut off? Let me know if you need me to resize them.
Edit again- The photos are all there, I could view them ok if I right clicked and opened in new tab.Re: Bosch Dishwasher not heating up and cycle never stops
Not to worry as I could view the full photo’s on photobucket anyway. I reckon the overheated chip is more associated to the power supply rather than the heater or motor circuit. In other words the power board that feeds the entire circuit.
Chances are that the circuit tends to overheat if you fail to turn the appliance off when it has finished. Whilst the appliance consumes a nominal amount of power in the ‘off/finished its cycle’ position, those PCB components continue to be energised. With that in mind it begs the question that perhaps, just perhaps, the components employed are not quite up for their intended purpose. Short term maybe but long term………? 😕
Re: Bosch Dishwasher not heating up and cycle never stops
Martin wrote:
Chances are that the circuit tends to overheat if you fail to turn the appliance off when it has finished.
The dishwasher was left on for ten days while we were on holiday 😳 It hasn’t worked since…….. :boops:
So do you reckon it is that chip then? The chips themselves are pennies but unfortunately I lack the necessary skills to remove and resolder.
Thanks again,
MikeRe: Bosch Dishwasher not heating up and cycle never stops
bikemike wrote:The dishwasher was left on for ten days while we were on holiday 😳 It hasn’t worked since…….. :boops:
Well, well, I thought as much. 😈
bikemike wrote:So do you reckon it is that chip then? The chips themselves are pennies but unfortunately I lack the necessary skills to remove and resolder.
Short answer, dunno. :con:
Well out of my knowledge base that one, sorry. 🙁
Re: Bosch Dishwasher not heating up and cycle never stops
does the machine run the main circulation pump ok ie is it spraying etc
Easy way to check the cycle is to take both side panels off and
watch what is going on.
If there is a faulty pressure switch or blockage on the heater it will fail to heat the water even with a good element.
The board looks ok to me with no obvious blown joints.Re: Bosch Dishwasher not heating up and cycle never stops
Hi, thanks everyone for their help on this one.
The machine runs ok, ie water comes in, sprays ok, and the pump empties the machine ok. The only thing it doesn’t do is heat. Where do I find the pressure switch? And how do I check the heater for blockages? I’m quite happy to strip it down, I just need to know what to look for!
Many Thanks again,
MikeRe: Bosch Dishwasher not heating up and cycle never stops
Its a while since I worked on one of these myself.
In between the heater element connections you will see a microswitch at 12 o’clock -behind this there is a small plunger
which is pushed out (and makes the switch) if there is sufficient water pressure.I have seen these stick-rare for the microswitch to fail -but again you check if the switch is working(prise out)
On top of the heater assembly there are two sensors-difficult to get at-I recall fixing a machine with a similar problem as one of them was o/c and giving no temp readback(rhs one I think)
You can check these with plug out and simple resistance checks.Not sure how to link to other posts but I have nicked a pic from
another thread below
Re: Bosch Dishwasher not heating up and cycle never stops
Ok, an update.
Checked the sensors as described, all are ok.
I found the fine gauze filter to be in poor condition (some of the plastic ribs had broken away) so replaced the filter assembly.
Reassembled and tested on the quick program- and it worked
So I filled it with dirty crockery and set it on the normal program- and it didn’t heat up
So, my question is- Does this point back to the control module?
I can’t see any other reason why it would heat up on one program but not another.
Any ideas chaps?
Many thanks again for all your help,
MikeRe: Bosch Dishwasher not heating up and cycle never stops
Can’t really see in your photo but isn’t that a dry joint I see here?
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