Ancient Bosch 0730301528

[johnmar]

Hi I’m new to this forum.

We have a Bosch GV620i (0730301528) which has given great service for more than 20 years. I have on occassion fitted replacement switches, also fittings for the hinges for the decor panel etc.

The current problem is that the washer stalls half way through a cycle. It will stick on a main wash until switched off. Selecting other programmes has no effect, UNTIL the machine has cooled down, then it is possible to select, say, Rinse so that the machine can be pumped out.

As an amateur, my guess is that the control unit, which is electro/mechanical, is siezing when hot.

Whilst still hot (and there is no activity) I can hear a humming from behind the front panel, which presumably means there is power being supplied to the components.

I have looked on Bosch’s part site and the diagram shows two components:

1.Control Unit 081155 £138 incl VAT
2. Motor 073603 £35 incl VAT

Can someone please let me know

1. Am I barking up the wrong tree?
2. Is the motor a part of the control unit, or just shown next to it in the diagram?
3.Any guesses as to which component has failed.

If there is a need to replace the control unit (as oposed to say the motor), then it may be worth considering a new machine. This will depend on locatin a unit which will accomodate the decor panel (semi integrated) also there will be a need to disturb the cabinets as the plinth is semi permanently fitted.

Any help and advice is greatly appreciated.

Many thanks

John

[Martin]

Re: Ancient Bosch 0730301528

Don’t give up on your ancient Bosch John without checking a few things out at least. There are a number of ‘possibles’ here that need checking….

Possibly the timer drive motor (073603) drive cog has slipped and not engaging with the timer gearbox?

Possibly the thermostat is overheating and the safety stat is cutting in? Which would explain your having to wait for it to cool down? New set of stats required there maybe?

Possibly the water level control is crudded up and needs a good flush out and hoses replaced?

You mentioned that you have to wait for the machine to cool down? So presumably the heater is working and its gets hot then does it? In that case you can rule out the need for a new Timer (phew – relief!) and consider new t/stats maybe?

As I am an ‘ancient Bosch repairer’ my guess is (at this stage at least) is the timer drive motor cogs not engaging. ???? 😕

[johnmar]

Re: Ancient Bosch 0730301528

Martin
Thank you so much for your rapid reply, much appreciated 😀

If I can add some more data..

Martin wrote:
Possibly the thermostat is overheating and the safety stat is cutting in? Which would explain your having to wait for it to cool down? New set of stats required there maybe?

If the safety stat was cutting in, would the machine still carry on with the washing cycle? At present it gets to a stage, YES it does heat up, but then sticks in that position until switched off.

Martin wrote:
Possibly the water level control is crudded up and needs a good flush out and hoses replaced?

I get the impression that the only reason there is water left in the machine is that it isn’t able to complete its cycle and get to the stage where it rinses and pumps out. If I change the setting to Rinse Only, after waiting (possibly for a cool down), then the system rapidly ‘clicks’ through the remaining programs, the indicator moves across and then clicks back to re-set and in the course of that pumps out.
Would what I have described require the drive cog to be engaged?

Martin wrote:Possibly the timer drive motor (073603) drive cog has slipped and not engaging with the timer gearbox?

My initial thoughts (purely speculating) was that it was a ‘drive-problem’ which would tie in with your suggestion of the cog not engaging with the timer. Could this happen on an intermitent basis?
I have just got my wife to run a Rinse Only program (cold water) to see if it completed, which it did. Possibly that points to a heat related problem ❓
Being an intermitent problem, could the timer drive motor itself be at fault, possibly heat related?

It’s good to learn that the timer doesn’t seem to be the problem 🙂

Your further thoughts would be most welcome.

This site and forum is a very valuable resource, particularly for accounants like me who would have been far happier being involved in things mechanical and electrical.

Thanks again

John

[clivejameson]

Re: Ancient Bosch 0730301528

Martin wrote:

my guess is (at this stage at least) is the timer drive motor cogs not engaging. ???? 😕

Gets my vote! :tup:

BTW Martin…did you mean you are an ancient engineer who repairs Bosch’s?? 😆

[Martin]

Re: Ancient Bosch 0730301528

clivejameson wrote:BTW Martin…did you mean you are an ancient engineer who repairs Bosch’s?? 😆

Correct whichever way you put it Clive. 🙂

johnmar wrote:YES it does heat up, but then sticks in that position until switched off.

It must be a thermostat fault if the wash contines and gets hotter and hotter I would think. I’d check the thermostats out first! 😉

[johnmar]

Re: Ancient Bosch 0730301528

Martin

If I’ve understood you correctly, you’re considering the possibility that a thermostat fault is allowing the system to overheat, BUT NOT sufficiently to trigger a complete shut-down. Also, that as a consequence, there is a temporary mechanical ‘breakdown’ in the timer-drive-train e.g. distortion due to heat, preventing the program from progressing.

At present I’ve yet to start physicaly investigating and have only looked at ‘exploded-drawings’ online. Also I can see that there ae several thermostats (tempreature-regulators) to consider. To investgate this competently and safely, I can see that I would probably require professional help. As a GUESS, I can see that it would not be difficult to spend approx £200, if the problem stopped there. Clearly this needs to be balanced against the cost of buying a new machine.

Am I exagerating?

Thanks again for your thoughts

Regards

John

[Martin]

Re: Ancient Bosch 0730301528

johnmar wrote:I can see that I would probably require professional help. As a GUESS, I can see that it would not be difficult to spend approx £200, if the problem stopped there.

Professional help shouldn’t come at that price, I know you live in Middlesex but £200 blimey, no way!

Click on the link below for advice from a local independent engineer (if there’s one listed in your area.) If you were local to me (for example) it would cost you £40 to have it fully checked out, so a worthwhile proposition perhaps, bearing in mind a current suitable replacement Bosch machine will set you back £350! 😉

[johnmar]

Re: Ancient Bosch 0730301528

Thanks Martin

I was trying to factor-in some actual repair and parts costs in addition to an ‘assessment-cost’ which is why my figure was looking high. It’s useful to know though, that the required level of professional help is available at affordable prices.

A DEVELOPMENT :rolls: Would you believe it? As an experienced engineer probably yes, the machine seems to have righted itself!! We tried it out on a different programme (50 C normal ), which was OK and then 50 C economy, which was the problem programme, also OK!

For the moment we’ll carry on and hope it continues to be OK.

Strangely enough, in the strainer filter there were many pieces of tubular-shaped limescale (never seen this before) which must have come from the heating element.

Anyway thanks again for your help.

Regards

John

[Martin]

Re: Ancient Bosch 0730301528

johnmar wrote:Strangely enough, in the strainer filter there were many pieces of tubular-shaped limescale (never seen this before) which must have come from the heating element.

Oh dear! We’re not using salt in the water softener unit then are we?

Always top-up regularly with salt on this old beast otherwise your troubles will progressively get worse!

[johnmar]

Re: Ancient Bosch 0730301528

Martin wrote:
Oh dear! We’re not using salt in the water softener unit then are we?

Obviusly not often enough 😳

We are in a VERY hard-water-area. Most of the water is softened apart from the dishwasher which shares its supply with the drinking water which is of course unsoftened.

I need to keep a better eye on this 8)

Regards
John

[Author]

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