# ISOMAC Tea stops working after 20 minutes heating up... and how I fixed it !



## marcuswar (Aug 19, 2013)

I have my machine setup on a simple plugin timer so that it comes on at 05:45 each weekday morning so that it's fully heated up and ready to go when I get up at 06:30. The timer turns off automatically at 07:00 by which time I have made my morning coffee "to go" and am on my way to work. This has worked fine for about 3 months or so but the other morning I got up to find that the boiler pressure gauge was reading only about 0.5 bar and neither the Red (heating) or Green (Ready) light were illuminated, although the power light was. A quick panic and frantic run around and my "backup" Classic was retrieved from storage to save the day. When I got home from work later I switched the Isomac on and it seemed to be working fine with boiler pressure rising steadily and once up to temperature the pressure was being maintained by the constant heating-ready-heating (red-green-red) cycle. Mmmm very strange .. anyway I wrapped the brew head in a towel and left the machine to fully heat up for 20mins but upon my return the exact same situation had occurred with the pressure down at 0.5 bar and neither the read or green light illuminated.

The pressurestat was my first suspicion but having replaced it with a new one (from Bella Barista £19.95) I have found that it hasn't rectified the fault. Having delved a little deeper into the machine with a multimeter and done some further research on the internet I think the issue is actually the transformer inside the Gimme Controller Box. It seems to overheat and turn off after 20mins and so no power is getting through to trip the internal relay that supplies power to the heating element (and red light). The controller boxes themselves are crazy prices (~£145) but I believe it should be possible to repair it as it is really such a simple device consisting of a transformer and a few relays, probably only about £5-£10 worth of parts (if that!).

The Giemme control box is situated underneath the boiler and is held in place by a single 8mm bolt that is accessible from underneath the machine. Removing the control box simply involves the removal of this 8mm bolt.









Having removed the Giemme box and opened it up a suitable compatible transformer would be the "MYRRA model 44089 :TRANSFORMER 1.5VA 18V". The Transformer is the large grey box with a small stepped top. Be careful not to break the 4 wire ribbon cable that joins both boards together while handling the two boards. I ordered a replacement transformer from eBay for *£5.18 delivered* (http://www.ebay.co.uk/itm/MYRRA-44089-TRANSFORMER-1-5VA-18V/171329859609). Farnell sell the same thing for £2.99 but they only accept non trade orders of a minimum value of £20 (http://uk.farnell.com/myrra/44089/transformer-1-5va-18v/dp/1689051).


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## marcuswar (Aug 19, 2013)

The transformer component arrived a few days later and so I set about unsoldering the existing transformer from the circuit board. This is a pretty straight forward affair but can be a little tricky to start of with as the transformer is held in place at 4 separate points. As the unit consists of two circuit boards joined by a 4 wire ribbon cable I taped the two boards together using a coffee coaster as a base. This helps reduce the risk of breaking the ribbon connections while man handling the board.









I found the easiest way to remove the transformer was to remove as much solder from each leg as possible (I used a solder sucker but copper braid would probably be easier) and then using as small jewellers screwdriver forced between the bottom of the transformer and the circuit board to gently apply pressure and lever the component from the board as I heated each leg again. Its a little awkward to get the first leg started but once you can get the screwdriver underneath it becomes much easier. Once the old transformer was removed the new transformer fitted perfectly and was easy to solder in place.

















The circuitboard was fitted back into its housing and the box replaced in the machine. I decided to place the control box with other way around for two reason. 1) so I could read the legend printed on it and 2) the transformer is now situated at the very bottom of the box which should be the coolest point of the machine which can only help future longevity. The downside of doing this is that the 240v relay output connections are now exposed on the very outside edge so may be more susceptible if a water leak occurred. I may actually fabricated pinch a small piece of plastic sheet between the top plate and the Giemme box in order act as a curtain and prevent any potential water ingress in the event of an internal leak.

Once the control box was replaced and the machine reassembled it was time to test. After first making sure that auto fill was working correctly by temporarily removing the connection from the boiler water probe and making sure the pump started, I left the machine turned on and heating up (with the probe lead replaced). An hour later the machine was still up to pressure and working great and the machine has been working fine all weekend. The repair has been a great success and a massive saving on buying a new control box... I'm well chuffed and hope this inspires others to give it go should the need arise.


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## espressotechno (Apr 11, 2011)

Obviously previous experience wtht a soldering iron !


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## marcuswar (Aug 19, 2013)

Only very basic experience, I've never designed or built anything from scratch just done very basic repairs. A bit like saying someone has previous electrical experience because they've wired a plug


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## centaursailing (Feb 27, 2012)

Congratulations Marcus, this is a very helpful thread, nice one!


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## marcuswar (Aug 19, 2013)

Thanks Rod.. hopefully it won't be useful... but if it the need arises it's nice to know what to do









During my investigations into the cause I found quite a few posts on various forums talking about similar behaviour etc, so I assume that it isn't a one off occurrence so nice to know that we don't have to spend over a £100 to fix it. There seems to be some suggestion that Isomac changed the supplier or the design of the box at some point in an attempt prevent this.


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## soundklinik (May 31, 2013)

Thanks Marcus,

a post worth gold for us Isomac owners, thanks for posting and congratulation on your repair...

Cheers, Karel


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## marcuswar (Aug 19, 2013)

Thanks Karel, knowledge is king and all that


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## espressotechno (Apr 11, 2011)

Gicar control boxes are superior (and more widely available) to Giemme boxes - most machine makers have switched over.


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## marcuswar (Aug 19, 2013)

I guess they all do the same job so it's just a case of connecting the correct terminals up to the correct wires. The only other box I've seen specifically marketed for the Isomac is the "Pro.El.Ind PRA1.3" , I'm guessing this is the "improved" model that Isomac moved over to for later machines.

When you say the Gicar control boxes are superior, in what way... do you mean they are more reliable?


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## PeterWoodx (Oct 5, 2015)

Marcus - thank you so much for this excellent, easy-to-follow post. I had the same problem with my Isomac Tea III Cool Touch and your solution worked like a dream. I was able to order two spare transformers from Farnell Element 14 for £6.74 including VAT and they arrived next day. My Giemme circuit board was different (just a single board) and the transformer was a 44122 but the same strategy worked really well. It's many years since I desoldered anything but all went to plan, so my electronics training plus a decent soldering iron and solder sucker (all from 1977) proved up to the job  Some similar symptoms appeared after a long day of use, so I relocated the Giemme box horizontally on the bottom of the machine to keep it as far from the heat as possible. All is well after two weeks of prolonged daily use, so I'm optimistic. Thanks again for your very valuable post!

Here's the link to Farnell in case anyone else needs it: http://uk.farnell.com/myrra/44122/transformer-9v-2va/dp/1689054


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## marcuswar (Aug 19, 2013)

Hi Peter, you're more than welcome and thank you for taking the time to thank me







. I'm glad my post has helped at least one other person. I hate to think of a machine being junked, or someone buying an overpriced Giemme box, all for the sake of a £6 part!


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## DavecUK (Aug 6, 2013)

With Gicar PID controllers, the transformers often fail and can be fixed by desoldering the existing Hahn tranformer and outboarding a £3 maplin one using some bell wire, the outboarded one stays much cooler and will last forever. The voltage controllers also leave much to be desired and the voltage can be dropped aroun 15% for much longer life, especially the display life.


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## 7493 (May 29, 2014)

DavecUK said:


> With Gicar PID controllers, the transformers often fail and can be fixed by desoldering the existing Hahn tranformer and outboarding a £3 maplin one using some bell wire, the outboarded one stays much cooler and will last forever. The voltage controllers also leave much to be desired and the voltage can be dropped aroun 15% for much longer life, especially the display life.


Does this apply to the Gicar PID in the Verona, Dave?


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## DavecUK (Aug 6, 2013)

Rob666 said:


> Does this apply to the Gicar PID in the Verona, Dave?


I would imagine it does, although I do know they use higher temp rated transformers now, so failure is less likely and I am pretty sure they changed the voltage controller as well to drop the voltage a tad across the circuit. The moral of the story is, we should be mopre willing to open up these (overly expensive) boxes and fix things, because usually it's a transformer, cap or relay that's gone bad


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## 7493 (May 29, 2014)

DavecUK said:


> I would imagine it does, although I do know they use higher temp rated transformers now, so failure is less likely and I am pretty sure they changed the voltage controller as well to drop the voltage a tad across the circuit. The moral of the story is, we should be mopre willing to open up these (overly expensive) boxes and fix things, because usually it's a transformer, cap or relay that's gone bad


Couldn't agree more Dave! In my time at the BBC we went from the engineers repairing at component level, when I started in 1972, to replacing boards by the 80's, to 'if it costs less than a grand and it's out of warranty, bin it'! by the time I left in 1996.

A good example would be an AEG dishwasher we had a few years ago. One of the microscopic surface mount switches behind the big buttons on the front panel had a dry joint. New panel = write off machine. Fix = an hour of annoyance dismantling and soldering/reassembling... Of course the 'elf and safety' brigade would have a fit!


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## marcuswar (Aug 19, 2013)

A few years ago the door seal on our LG washing machine started to leak. LG wanted something like £80 for a new one so I ended up bodging a repair with some silicone and a puncture repair patch. It still dripped slightly so we had to make sure we placed a towel on the floor under the door whenever we used it. Started watching eBay and after a week or so I found someone selling the same model that had a fault with the drain pump. It was fairly local (about 20miles away) and I ended up "winning" it for £30. Drove over and picked it up the same day. Brought it home and put it in the garage. Pulled off the door seal and fitted it our machine and voila, fixed for £30 instead of £80 and I've got a tonne of spare parts for future use.

About a year later the drum bearing started to make a nasty noise and eventually seized. I spent a couple of hours removing the drum from the "spare" machine in the garage and fitting it into our machine and once again it's all working again .

"I love it when a plan comes together"


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## DavecUK (Aug 6, 2013)

marcuswar said:


> About a year later the drum bearing started to make a nasty noise and eventually seized. I spent a couple of hours removing the drum from the "spare" machine in the garage and fitting it into our machine and once again it's all working again .
> 
> "I love it when a plan comes together"


So lemme get this right, you saved 50 quid on a door seal by collecting an old machine, cluttering up your garage with it for years and gradually robbing it for parts over the next god knows how many years....that is true dedication to the reduce, reuse, recycle philosophy......Me I simply bought a Miele washing machine. it's now over 10 years old and does 2-3 washes per day 6 days per week (my wifes home business requires lots of towels get washed all the time). This equates so far to 30 years + of washing in the normal home.

I used to have a Beko and that failed completely within 13 months....drum bearing shot!


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## marcuswar (Aug 19, 2013)

Yes that exactly right DavecUK... you sound just like my wife







You say "Dedication to the reduce, reuse, recycle philosophy", my wife shortens this to "miser"! From my point of view the more I save on frivolous luxuries like washing machines then the more money I have to spend on essentials like Coffee.

The LG (direct drive) was about 12 years old when the bearing went so hopefully it'll survive another decade. I do agree that Miele make quality products though and are one of the few manufactures that make all their own stuff rather than rebadging other manufactures machines.


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## 7493 (May 29, 2014)

@DavecUK I'm glad to hear your Miele experience has been happier than ours. Bought a Miele dishwasher after believing the hype and about a month out of its five year warranty it started leaking and turning itself off with an error code. I did have a poke about but gave in and called in the local Miele engineer. The problem was failed seals on a plastic return pipe. The cost of the part, £180 !!!!!!!! That for a couple of feet of moulded plastic pipe with a seal at each end. Of course, they don't supply the seals on their own. Apparently a common failure on these machines. Next time it breaks I'm buying a Bosch for around £300 and I don't care if it fails after five years, I'll either fix it myself or buy another one. I'm also informed by the same engineer and another local one that the Miele washing machines of today are a pale shadow of the ones made 20 years ago. Motor failures at £500 a pop are quite common...


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## DavecUK (Aug 6, 2013)

Rob666 said:


> @DavecUK I'm glad to hear your Miele experience has been happier than ours. Bought a Miele dishwasher after believing the hype and about a month out of its five year warranty it started leaking and turning itself off with an error code. I did have a poke about but gave in and called in the local Miele engineer.


Hmm..perhaps things have changed since we bought ours 10 or 11 years ago. It used to say on their web site that the machines were designed to last at least 20 years. I did have to change a door seal on the Miele and was impressed with how well it was made compared to others.....and no the door seal did not wear out. My wife left a small piece of clothing trapped in it when she closed the door and when the cycle started it pulled back into the drum, ripping the seal. it's how 90% of door seal damage occurs and either rips them or starts them off leaking.

it was annoying that I had to buy the genuine part for around £80, but due to the quality of the machine it only took me around 20 minutes to fit it.


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## 7493 (May 29, 2014)

According to both the engineers I spoke to things have indeed changed! If you have one of the older ones I would look after it!


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## Nikiman (Feb 15, 2021)

Hey!

I just came across this thread and see it is really relevant. Thanks for posting this. However, I`m in a situation where I`ve already have purchased GICAR box to replace the GIEMME on my ISOMAC TEA ( Mod 2002). Does anyone have knowledge/ideas how to rewire from GIEMME to GICAR?

Mod GIEMME: RLO 1E/1S// 3C/F ( Have 9 Pins) ...same one as in this thread









MOD GICAR: RL 30 Micro ST ( COD. 9.1.40.52G. 02 ) ...( Have 8 pins).

Example schematic: https://www,chisko.com/prodotti/regolatore-livello-rl30-ustf-livello-z-230vac-gicar--914852g-02-ecm-vari-133141.aspx

I`ve searched in many forums, and apparently there are many different models and versions that I can`t use.

The question is then: How can I connect right PIN on GICAR that correlates to GIEMME pin?

Appreciate your answers  .

Niki


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## KentJesus (Sep 28, 2021)

Ended up here with the same question, how to wire when replacing a Giemme control box (RLO 1E/1S/3C/F) with a Gicar. These schematics helped a lot!


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## Brew-sters millions (7 mo ago)

Well , this is a very old thread, I will just leave this here. If you have a 115v unit then the zettler BV301S12020 will fit and works perfectly… it’s 12v on secondaries and is 2va so it’s taller..


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## bernieold (6 mo ago)

Same TEA problem here. Replacing Trafo solved the issue. Many thanks.


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