# Bezzera Magica Low Brew Temperature



## sturner04659 (Jul 9, 2017)

Hi,

I picked up a Bezzera Magica a couple of months ago for an absolute bargain and have been trying to get decent espresso out of it since.

I have noticed that the brew temperature is far below where it should be so am looking for some troubleshooting guidance to help me find where the problem is.

I set the machine to come on in the morning about an hour before I use it so I assume it should be up to temperature by then. The steam boiler rests at around 1.2 bar. The steam and hot water wands work as expected so I don't think there is an issue with the boiler. The group is too hot to touch for more than an instant so I also don't believe this issue is due to a thermosyphon stall.

I've found that sometimes if I make a coffee and leave the machine on at the weekend, then make more later in the day, I get much better results and can see when I flush more steam rising from the drip tray so the temperature must be higher.

Another issue I have is a screeching noise when brewing which from other forum posts I have read, is probably resonance in the opv, but shouldn't be causing a problem.

I'm trying to focus on the brew temp problem first but in case the two are connected though I should mention the screeching.

The machine was serviced about a month before I bought it and I saw the invoice to prove it. The boiler was fully descaled so I am currently working under the assumption the problem is not scale in the HX part of the boiler.

Does anyone have any experience in troubleshooting a problem like this? From other posts I have read for similar issues, suggestions are generally to check the scale condition of the mushroom / brew valve, or to effectively bleed the thermosyphon circuit. Do these sound like reasonable first steps?

The machine is 5 years old. I don't have a group thermometer so if anyone knows where I can pick one up in the uk at a reasonably price that would be appreciated!

Thanks for any advice / help!

Simon


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## DavecUK (Aug 6, 2013)

The group even when too cool to get adequate brew temps can still feel "too hot to touch for more than an instant".

How did you acquire it and do you know where (in the country) the machine was actually being used. Who did the servicing, was it the vendor? Bleeding the thermosyphon circuit isn't really a thing, it bleeds every time you pull a shot. If the expansion valve (OPV as you call it) is leaking then you can always have a look at the tube that comes from it and see if water is slowly coming out (it will slowly come out after a shot or when first heating the machine of course).

*The best first step would be for you to describe what you used, exactly how you checked the brew temperature and what it is reading?*


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## sturner04659 (Jul 9, 2017)

Thanks for your suggestions!

I bought it off Gumtree. It was being used in Clapham. Servicing was performed by Backup Coffee.

I haven't done any real reading of the temperature it is just clear that it is low. I'm getting no crema and generally watery and thin extractions, if I drink the shot it is warm rather than hot even though it has been extracted into a heated cup (while I'm sure my technique isn't anything close to perfect, I've come from a PID gaggia classic and know how to get a decent shot). I'm getting no flash boiling when I flush the machine from idle.

Is there a good way of checking temperature without specialist equipment?


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## John Yossarian (Feb 2, 2016)

Bezzera have got a HX that is kind of unique, I am talking about my experience with an older model BZ35e. This was the reason I did not have to flush much. I do not have experience with your model but if the HX has not been descaled, (it might have to be descaled separately from the boiler) most likely the heat exchange is not good enough to get the brewing water up to the right temperature irrespective of whether the boiler is hot, and as you describe it it seems to be in the right ball park at 1.2 bar.

I cannot think of anything else that springs to mind but someone might throw a bright idea.

Good luck!


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## kennyboy993 (Jan 23, 2017)

The magicas are very similar to ecm hx internally believe.

If so they are tuned especially to not need as much of a cooling flush as some other hx - ie the groups run cooler.... relatively.

If it's topping out at 1.2 that could be quite cool in my experience - would mean its bottoming out at around 0.95 bar? You did say 'resting' at 1.2 though thought I'd check.

Even at that pressure you should get flash boiling though after a long idle. I can imagine at around 1.2 though, even after a relatively long 20 minute idle, the amount of flash boiling could be small enough to be easy not to notice..... especially if you've been running the hot water tap and cooling the boiler. Something to consider.

Either way though I agree you really need some way of getting an idea of temp...... where are you in the UK? I might be able lend you my e61 group head thermometer


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## John Yossarian (Feb 2, 2016)

Hi Kenny

I have to say for the record, you are a very cool guy and I would happily have a pint with you







. If you ever get nearby Stockport give me a shout







.

Cheers,

John



kennyboy993 said:


> The magicas are very similar to ecm hx internally believe.
> 
> If so they are tuned especially to not need as much of a cooling flush as some other hx - ie the groups run cooler.... relatively.
> 
> ...


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## kennyboy993 (Jan 23, 2017)

Thanks John, nice thing to say mate. I'm over Manchester occasionally will give I a shout ;-)


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## DavecUK (Aug 6, 2013)

John Yossarian said:


> Bezzera have got a HX that is kind of unique, I am talking about my experience with an older model BZ35e. This was the reason I did not have to flush much. I do not have experience with your model but if the HX has not been descaled, (it might have to be descaled separately from the boiler) most likely the heat exchange is not good enough to get the brewing water up to the right temperature irrespective of whether the boiler is hot, and as you describe it it seems to be in the right ball park at 1.2 bar.
> 
> I cannot think of anything else that springs to mind but someone might throw a bright idea.
> 
> Good luck!


This sounds like a likely culprit.........the HX being a separate tube within the main boiler is harder to descale, perhaps they descaled the main boiler, but not the HX. If it's been used in Clapham, very hard water, so more than likely scaled up badly. Get polystyrene cup, place thermometer or whatever you have in cup and run brew water only into cup. Does temperature read 75C? You will of course need a thermometer, get a 0 - 200C wone of ebay for £2 delivered.

https://www.ebay.co.uk/itm/Glass-Celsius-thermometer-30degree-To-100degree-300mm-Laboratory-Glassware-XBUK/142751630501?var=441754140169&hash=item213ca904a5:m:m5EVZIGRwO76hA2ESEkj2vg


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## sturner04659 (Jul 9, 2017)

Thanks again for your advice guys!

@kennyboy993 I'd say the boiler pressure bottoms out at 1.2 or close to. I've never seen it below 1.1 or above 1.3 when the machine is idle.

I'm based in Kingston on Thames so pretty far away!

@DavecUK I checked the OPV tube back into the water tank and there was no flow while idle.

I'll try to get back in touch with the company who serviced it and see if they descaled the HX, not sure if I'll believe them to be honest.

If they didn't (or I decide I don't believe them) is there a way to descaled it without taking the boiler out?

I have a milk jug thermometer, will that be accurate enough for taking a measurement (it is within 2 degrees of the central heating thermostat in the room)?

Thanks,

Simon


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## DavecUK (Aug 6, 2013)

Try the milk jug thermostat for sure. There won't be any flow back from the expansion valve when idle, unless you have just pulled water through the HX and the incoming water is heating and "expanding". If not, things are in a steady state and nothing will come from the expansion valve tube.

To descale the HX (ensure the boiler isn't going to autofill, so trigger the autofill by drawing hot water from the tap). Then put some fairly concentrated descaler in the tank. Run water through the group a 3 or 4 times for 5 seconds each time, then leave the machine for a few hours. Then repeat, after which you can put clean water in the tank and repeat the same procedure without the wait to flush the HX clear of descaler.


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## Syenitic (Dec 1, 2013)

Hi @DavecUK, that is perhaps the simplest explanation of how to descale an HX I ever saw. Happy to go ahead now I know I don't need to get inside the casework and disconnect wires etc.

What constitutes 'a fairly concentrated descaler'? I have a kilo of citric acid powder (used for brewing and making old fashioned ginger beer), any ideas of grams/ml water?

Mainly a user of volvic/ashbeck with a bit of others when I cant grab those easily, and looked inside the group (under the knut) and could see no real evidence of scale.


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## DavecUK (Aug 6, 2013)

300ml hot water and dissolve around 100g into it, 150 if you can. If when flushing it comes out clear and bright green, then they did descale and you can stop. if it's quite cloudy and murky, then they lied and you can continue.


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## sturner04659 (Jul 9, 2017)

Ok I'm going to give descaling a go. Do you know of a good descaling product that is not too harsh etc? I have used puly caf in the past.


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## sturner04659 (Jul 9, 2017)

@DavecUK I've been stupidly busy moving house, holiday, work etc so only just got round to doing the descale as you suggested. First few shots I've pulled afterwards are much less watery and have a much better crema. Also the screeching noise has gone too!

I'll see how it goes over the next week but it looks like a simple descale has fixed both my issues!

Thanks very much for your advice!


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## DavecUK (Aug 6, 2013)

I am glad it helped you solve the problem.


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## sturner04659 (Jul 9, 2017)

Hi,

Reviving this thread as I've found that my shots have now gone back to being watery. I can tell the brew temp is lower as I'm getting very little flash boiling. I'm brewing with zero flushing at the moment as it's the only way I'm getting any kind of decent shot.

I'm thinking of trying descaling again as this definitely worked the first time, but I'm worried about damaging the machine by using this strong descaling solution too many times (I've done it twice now in a period of 6 months).

Do you think I need to worry about this or just go for the descaling?

Also any idea why the machine could have reverted back to lower temp?

Thanks!

Simon


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## MediumRoastSteam (Jul 7, 2015)

sturner04659 said:


> Hi,
> 
> Reviving this thread as I've found that my shots have now gone back to being watery. I can tell the brew temp is lower as I'm getting very little flash boiling. I'm brewing with zero flushing at the moment as it's the only way I'm getting any kind of decent shot.
> 
> ...


Out of curiosity, what's the water that goes into the machine like? Bottled? Filter? Tap? If bottled, which one? If any of the latter, how hard is the water?


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## sturner04659 (Jul 9, 2017)

I've only used either ashbeck from Tesco or waitrose essential.

I bought it early last year.

I'm assuming the previous owner used tap water but it was serviced not long before I bought it and they showed me the invoice. Whoever serviced it didn't properly descale the HX from what I've seen come out when I've descale it (very cloudy).


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## Nikko (Aug 20, 2014)

The temperature of the brew water depends on the temperature of the steam boiler. Is the steam boiler at the correct temperature (pressure)?


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## sturner04659 (Jul 9, 2017)

Yeah steam pressure is fine and has always been the stable (if you read my original post I described the problem in a bit more detail)


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## Nikko (Aug 20, 2014)

In that case it can only be scale reducing heat transfer or some blockage reducing the natural circulation


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