Bosch SGS5312GB – cycles taking too long

[davepi]

My Bosch SGS5312GB has started to take an excessive amount of time to complete a cycle. Instead of taking the published 83 minutes for the Eco 55 wash, it is taking in excess of 140 minutes. What are the possible causes of this?

TIA

Dave

[Martin]

Re: Bosch SGS5312GB – cycles taking too long

davepi wrote:What are the possible causes of this?

Gunged up soil sensor in the heater unit is the problem. That is caused by using cheap detergent or/or not using salt in the salt container when you should (hard water and all that!).

2 things you can do to try curing it are firstly, buy some dishwasher cleaning tablets and follow the instructions. Secondly, use a good quality detergent like Fairy Active Bursts and again, follow the instruction on the package! 😉

Hope that sorts it for you? 🙂

[davepi]

Re: Bosch SGS5312GB – cycles taking too long

Martin wrote:Gunged up soil sensor in the heater unit is the problem. That is caused by using cheap detergent or/or not using salt in the salt container when you should (hard water and all that!).

2 things you can do to try curing it are firstly, buy some dishwasher cleaning tablets and follow the instructions. Secondly, use a good quality detergent like Fairy Active Bursts and again, follow the instruction on the package! 😉

Hope that sorts it for you? 🙂

Thanks. I’ve run the machine with some Finish dishwasher cleaning fluid and the cycles have now reduced in time a but still taking a couple of hours. Where is the soil sensor and how easy is it to gain access to clean it?

thanks

[gegsy]

Re: Bosch SGS5312GB – cycles taking too long

The soil sensor or to give it its correct title Turbidity Sensor is mounted in the instantaneous heater unit. You can’t gain access to the part of it that will be gunged, only the sensor pcb itself is accessible.

Keep running it through on hot washes to see if gets any better. Failing that the sensors “may” be faulty.

Greg

[davepi]

Re: Bosch SGS5312GB – cycles taking too long

gegsy wrote:The soil sensor or to give it its correct title Turbidity Sensor is mounted in the instantaneous heater unit. You can’t gain access to the part of it that will be gunged, only the sensor pcb itself is accessible.

Keep running it through on hot washes to see if gets any better. Failing that the sensors “may” be faulty.

Greg

I’ve run it several times on the hot wash (65) and it is continuing to take over three hours. As well as the Turbidity Sensor, could there be other problems such as:

1. The element taking too long to heat up the water
2. A faulty thermostat
3. The fact that I installed a water softener a couple of months ago.

With regards to the water softener, I have turned off the dishwasher’s water softener and have stopped putting salt in it (the salt indicator is off so the machine is not asking for any). The house water softener is an electronic one which has been set up to soften only as much as is needed for the level of hardness of the incoming water main. Could this water softener be the problem and if so, what could it have done to the machine? I have noticed a small amount of froth in the bottom of the machine at the end of the cycle, but nothing excessive.

thanks

Dave

[Martin]

Re: Bosch SGS5312GB – cycles taking too long

davepi wrote:1. The element taking too long to heat up the water

Whoops!…I’ve just realised that a Bosch SGS5312GB doesn’t have a ‘Turbidity Sensor’ anway, so that idea doesn’t apply, sorry to confuse on that issue.

The fault is therefore more likely to be the heater not working (washing in cold etc?) and the cause for this is a burnt out relay terminal on the main circuit board….! 😯

[davepi]

Re: Bosch SGS5312GB – cycles taking too long

Yeah, had that problem a couple of years ago and fixed it; only the darlington array that allows the micro to drive the relays also got taken out! A trip to RS and 50p sorted that out.

The machine is heating the water, but I wonder if it’s happening too slowly or the thermostat is bust meaning it gets too hot – I will check that.

I had a look at the filter in the base of the machine, that you’re meant to clean every week, and found a layer of milky gunge over it – something to do with the softened water perhaps? Bosch tell me that they don’t advise people to run their machines from a water softener, but wouldn’t/couldn’t tell me why. Anyone know why that is?

The machine is about 7 years old – at the end of the day is it worth repairing?

[Martin]

Re: Bosch SGS5312GB – cycles taking too long

davepi wrote:Bosch tell me that they don’t advise people to run their machines from a water softener, but wouldn’t/couldn’t tell me why.

Only because it is more difficult to determine the effectiveness of an external water softening device when calculating the required doseage of detergent. In case of things like preventing overfoaming and/or operating with a possible ‘polluted’ water supply etc. All a load of tosh if truth be know, but manufacturers have to cover their rear ends, if you catch my drift?

davepi wrote:The machine is about 7 years old – at the end of the day is it worth repairing?

Your call on that Dave really bearing in mind a replacement Bosch would set you back £350.

The “milky gunge” by the way sounds to me like an undesolved dishwasher tablet? Are you sure the machine is filling with a full compliment of water and that the internal fill system isn’t similarly gunged up?

[davepi]

Re: Bosch SGS5312GB – cycles taking too long

Right, I have now checked the temperature and it struggles to hit 47 deg after an hour on the 65 deg wash. It MUST be the element. I don’t think it’s the dodgy relay solder joint on the control board, as if that had gone high-resistance it would have burned out by now.

How easy is it to check and change the element?

Dave

[superfix]

Re: Bosch SGS5312GB – cycles taking too long

How easy is it to check and change the element?

Very easy to check with multimeter set to ohms.

Very difficult to change as a DIY job.

:zap: Pull the plug first please.

[Penguin45]

Re: Bosch SGS5312GB – cycles taking too long

If the thing is underfilling due to the fat deposits in the front left transfer pipe, there may be insufficient water circulating to operate the diaphragm switch on the end of the heater box.

Penguin45.

[jeremy]

Re: Bosch SGS5312GB – cycles taking too long

why not just get someone to repair it that knows what they are doing ???

[Penguin45]

Re: Bosch SGS5312GB – cycles taking too long

The poster appears to be intent on working this out for himself. If you have nothing constructive to add, please leave the thread alone.

Penguin45.

[davepi]

Re: Bosch SGS5312GB – cycles taking too long

Penguin45 wrote:The poster appears to be intent on working this out for himself. If you have nothing constructive to add, please leave the thread alone.

That was the plan, but even with a degree in Electrical and Electronic Engineering, I have neither a service manual, training nor extensive experience of repairing dishwashers!

Is the machine’s plumbing that has been alluded to and the heater element accessed from inside the machine, or do I need to take off any back or side covers to get at them?

I do enjoy fixing things myself and am willing to work it out for myself, but being a lazy b****r, have been appreciative of the advice that people have given.

thanks

davepi

[Martin]

Re: Bosch SGS5312GB – cycles taking too long

davepi wrote:Is the machine’s plumbing that has been alluded to and the heater element accessed from inside the machine, or do I need to take off any back or side covers to get at them?

You know, for a guy that has a degree in Electrical and Electronic Engineering, you’re pretty smart. :tup:

I think you may be getting warm, even if your machine isn’t. 🙂

[Author]

Posts