Nemox - Can't Reach Temp

[BeanieWeanie]

Okay, first thing this morning I did as advised and primed it, but I could tell that it was already full by the sound. Then I moved on to test the temperature.

Long version:
Instead of your advised warm up time of 15 minutes I walked away and while having my morning cup from my Mocha Pot I forgot about the machine. It ended up warming for 1/2 hour. I felt the boiler which was hot, but not extreme. I then drew about 1/2 cup of water from the group which turned out to be about 43°C (yes I found a celcius thermometer). I then attempted steam which wasn't possible probably due of the low temp. Steam starts at 100°C. From the steam wand I drew some water that turned out to be about 38°C. I drew a total of about a cup of water total at this point. Seems the more water I drew the lower the temp would go as it didn't have enough time to heat more. 20 minutes later (now 50 minutes total) I attempted steam again and still got nothing, but the water from the steam wand was at 43°C, same as what I pulled from the group earlier. The boiler was again hot, but not extreme. After an additional 20 minutes (now 1 hour 10 minutes) slight warming up sounds starting from the boiler which has become almost too hot to touch. After 1.5 hours the light remained on with the boiler still making sounds as though it's warming up, but still not these almost knocking sounds that I used to hear. 7 minutes later I drew a 3/4 cup of water from the group which came out at 50°C. I then turned the machine off.

Short version:
After 1 hour 37 minutes the machine reached 50°C. The temp light remained on.

What would cause the machine to take so long to warm up and yet still never reach the appropriate temp? Would a bad element act this way? Something else?

[BeanieWeanie]

Thanks again Matt. I'm pretty sure I've been priming it correctly, but I'll give this another shot in the morning.

I don't have a diagram/schematic. The machine is a Nemox Caffe Dell Opera. It's mostly the same as the Lelit PL042 Combi.

[MattyRay]

BTW not sure if this might be your problem, but I found this thread below:

http://coffeesnobs.com.au/brewing-eq...ra-manual.html

Matt

[MattyRay]

Hi Tony,

Is there any way you could post or link an electrical wiring diagram for your exact machine? If possible to do this, it would assist greatly with long distance fault finding :-)

Regards,

Matt

[BeanieWeanie]

G'day Tony,

The hard plastic insulation on coffee machine terminals can tend to get brittle over time, but electrical tape may not last very long due to the heat. Perhaps some heat shrink over the connector would be a better option. Another option is to use some high temperature silicone impregnated fibreglass sleeving over the area.

Regarding disconnecting the parts, they can be left on the machine, but make sure the terminals are not connected to other parts. If someone knows what they are doing, then yes it is possible to test a lot of parts in circuit, but if you are not sure, the best way is to electrically disconnect the part.

Cheers,

Matt

Thanks Matt. I do have plenty of heat shrink tubing, thanks for the reminder. Excuse the senior moment.

I'll start tearing it down tomorrow and see what we come up with.

You guys are a real awesome bunch. Thanks

[MattyRay]

G'day Tony,

The hard plastic insulation on coffee machine terminals can tend to get brittle over time, but electrical tape may not last very long due to the heat. Perhaps some heat shrink over the connector would be a better option. Another option is to use some high temperature silicone impregnated fibreglass sleeving over the area.

Regarding disconnecting the parts, they can be left on the machine, but make sure the terminals are not connected to other parts. If someone knows what they are doing, then yes it is possible to test a lot of parts in circuit, but if you are not sure, the best way is to electrically disconnect the part.

Cheers,

Matt

[BeanieWeanie]

To the OP, a possible cause is a poor connection to the element, thermostat etc. this can often be indicated by a discoloured connection, often black or blue in colour.

I've looked at all the connections and found none as you described. I have, however, found that most of the plastic that shields the actual connectors have become brittle. One crumbled when I was attempting to disconnect it. I wrapped it with electrical tape to avoid a possible short/arc, is that okay? The actual metal connectors seem fine as far as I can tell.

Another tip, when measuring a part for resistance, it is usually best to completely disconnect it to stop the possibility of other items in the machine from affecting the reading.

Not to be anal, just clear, when you say "disconnect it" are you meaning to completely remove it and then test it? Or in this case are you saying to leave the element installed, yet disconnect all it's connectors at the terminals?

Tony

[MattyRay]

I thought elements generally either work or dont, not just work partially to give warm instead of hot?

Cheers

Correct, this is pretty much always the case.

To the OP, a possible cause is a poor connection to the element, thermostat etc. this can often be indicated by a discoloured connection, often black or blue in colour.

Another tip, when measuring a part for resistance, it is usually best to completely disconnect it to stop the possibility of other items in the machine from affecting the reading.

Regards,

Matt.

[BeanieWeanie]

The resistance measurement is with machine unplugged and element disconnected. If you are not familiar with electrics best to leave to experts and avoid the afro!

Finding a so called expert in my area has been a no go for months, unless I'm willing to ship to NY, which wouldn't make $$ sense. Seem guys around here only work on restaurant machines or tell you to throw it away and replace it with some cheap piece of garbage. This is why the machine's been down so long and why I've finally given up trying to locate an "expert" and instead do it myself. If I mess up the machine worse case I continue on with the mocha pot that we've grown used to. I just hate the fact of this machine sitting on my kitchen counter like a large paper weight.

If the power is off to do this test I shouldn't have a problem doing it. If I have to watch a dozen and 1 Youtube videos on the subject to make sure I do it right, I'll do so.

Sounds like your machine is telling the element to heat up (light on always) but its not getting there, ie switches and thermostats seem ok. I thought elements generally either work or dont, not just work partially to give warm instead of hot? Maybe someone else can chime in.

I may just tear it down and have a look at the element as it's just sitting unusable anyway. At the least, I'll give everything a good cleaning and who knows maybe learn a thing or two. I'll post what I find, but it may be a few days.

[artman]

The resistance measurement is with machine unplugged and element disconnected. If you are not familiar with electrics best to leave to experts and avoid the afro!

Sounds like your machine is telling the element to heat up (light on always) but its not getting there, ie switches and thermostats seem ok. I thought elements generally either work or dont, not just work partially to give warm instead of hot? Maybe someone else can chime in.

Cheers

[BeanieWeanie]

I would look for discolouration, blistering etc. Pretty sure the coffeeco website had some pics of bad elements (was a few years ago I had a look).

Cool I'll look for it. This is the same place I found the guide.

Resistance = (volts*volts)/power

This will give you an approximation of the resistance reading you should be getting across the element terminals.

If this is a test that the machine has to have power running through it, I'll have to research it as I obviously don't want to do it wrong and end up with a wild afro. I'm uncertain as to how to set the meter. [/QUOTE]

Is your machine 240 or 120volts? Are you talking farenheit or celcius? This will clear up confusion.

120v, plugged into a standard outlet here in the U.S. and Fahrenheit as I'm not familiar with C, but will convert with an online calculator if necessary. Whatever makes it easier as I appreciate the help.

[BeanieWeanie]

How are you measuring your brew water temperature?

Thanks for your reply Mal, With a thermometer and a coffee cup. The 120°F was a fluke the other day, everything since has been cold, room temperature, both from the group and steam. The 120°F was probably due to the period it's been down, but that's just a guess. Again, nothing inside gets hot either and I no longer hear the machine warming up as I had for near 10 years.

[BeanieWeanie]

The water pump is rated at 120V, is this coffee machine being run on 120v?

Yes, that's standard here.

[artman]

What should I be looking for? Corosion? Deposits? ?

I would look for discolouration, blistering etc. Pretty sure the coffeeco website had some pics of bad elements (was a few years ago I had a look).

The same test as earlier, continuity? Sorry to ask, I never understood electrical, yet I pick up what I can online.

Edit: With the element still installed I tested the continuity across terminals and got a -343. I'll do the same test once I have it out, but is this an additional indicator that it's bad?

Resistance = (volts*volts)/power

This will give you an approximation of the resistance reading you should be getting across the element terminals.

Is your machine 240 or 120volts? Are you talking farenheit or celcius? This will clear up confusion.

Cheers

[Dimal]

How are you measuring your brew water temperature?
In-stream measurement under the Group is hopelessly inadequate to be of any actual use as a reference...

Suggest you have a read through this post to give you a better idea of what is required.
http://coffeesnobs.com.au/general-co...rature.html#10

Mal.