What type is the coffee boiler temp sensor?

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AndyPanda

What type is the coffee boiler temp sensor?

Post by AndyPanda »

Does anyone know what type of sensor is used for the brew boiler? It's not a K or T type since there is no polarity (you can connect the wires either direction according to Chris Coffee and I tested reversing the wires and it works either way). Chris Coffee couldn't tell me what type it is, they don't know.

I'm thinking it must be a thermistor or RTD. Hoping someone here knows.
goodboyr
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Re: What type is the coffee boiler temp sensor?

Post by goodboyr »

Pt1000 rtd

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AndyPanda

Re: What type is the coffee boiler temp sensor?

Post by AndyPanda »

Thanks! How were you able to find out?

I bought my machine used and the previous owner had replaced it but I don't know if they bought from Chris Coffee (thinking they didn't since the connectors were spliced on and if ordered from CC the sensor would have come with the connectors right?) or if they bought a replacement of unknown quality. But it does look like the one from CC, other than not having had the connectors.

This may be normal for the S1 but mine seems really slow to register a change. I flush 4oz and it's a good 10-15 seconds before it notices and then when it does notice, all of the LEDs go out as though it suddenly noticed a drop from 96C to 90C. I would think I could flush a little bit and notice a 1C or 2C drop on the LEDs .... or is that normal behavior?

Anyway ... I had thought of getting an exposed sensor (instead of embedded in all that epoxy inside a metal sheath) so it could react faster. Have you had good luck with replacement sensors from somewhere other than Chris Coffee?
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Re: What type is the coffee boiler temp sensor?

Post by goodboyr »

My answer applies to the dream version and the newer sensors for the Vivaldi's. In any case, I am somewhat of an expert on the dream sensors, given my bad experiences with them in the early days of the dream. You can search on my user name to read those threads. I've only used sensors from ccs however at the height of my frustration I did try to source alternatives. The issue with the dream is that they have a certain depth and thread pitch. In any case the problem has been solved for me and my machine has been rock solid. I've never had an issue with reaction time, unless the sensor has failed.

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La Spaziale Dream and Baratza Sette 270W
AndyPanda

Re: What type is the coffee boiler temp sensor?

Post by AndyPanda »

I'm somewhat curious. My brew boiler temp sensor slides into the boiler inside a copper tube just above the heating element. When I read any of the sales brochures for the Vivaldi II they talk about a new sensor that is submerged directly and much faster responding than the old one. (see below from the ad). Is mine the old one or is mine the new one discussed in the ad? If mine is this new one, what was the previous style like?


Decreased delta: The original Vivaldi S1 needs to detect
a temperature drop of one degree Celsius before the
heater is activated. The new Vivaldi II activates the heater
with the detection of a temperature drop of just one half
degree Celsius. Simply put, it makes the temperature
accuracy that much more precise in the group boiler
and enhances the steam boilers performance.
Updated temperature sensing probe: The new probe
is actually submerged directly into the boilers. This probe
has proven to be more reliable than the previous style
and has a quicker reaction time.
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chas
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Re: What type is the coffee boiler temp sensor?

Post by chas »

RTD PT1000 Type 501
PT1000 RTD Temp Sensor Chart.jpg
PT1000 RTD Temp Sensor Chart.jpg (133.56 KiB) Viewed 13799 times
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chas
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Re: What type is the coffee boiler temp sensor?

Post by chas »

If you are looking for better group temperature control, you may want to emulate the change they made to the Dream group boiler temp probe design. In the original S1, both boilers used the metal well design where the temp probe was on the end of two long wires and you just pushed the probe down to the bottom of the well. Later they changed the design of the steam boiler to just using a shorty one piece temp probe and removed the well. In the Dream they use the shorty probe for both boilers but they swapped the position of the probe and stuck it in the hole in the top of the boiler. Both holes are tapped the same. You can remove the probe and well from the back end of your group boiler, then remove the allen head bolt from the top hole and screw it into the back hole. The new shorty probe will then screw right into the top hole as shown below.

The only downside is that they changed the style of connector on these probes so you would find that you can't just plug this new probe into the existing connectors. If you decide to try this, be sure to order the probe from Chris Coffee and ask if they have the other female connector end they could send you. Otherwise you'll be in for some splicing.

https://www.chriscoffee.com/Temperature ... /11502.htm ($59 = Free shipping)

if you just want to stick with your current solution, buy this part: (it is $26 cheaper, though cheap enough that you'll have to add in shipping which is free for the Dream sensor - so some of that savings gets eaten up in cross country shipping fees)

https://www.chriscoffee.com/Vivaldi-Tem ... p/7540.htm
SBTP.png
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goodboyr
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Re: RE: Re: What type is the coffee boiler temp sensor?

Post by goodboyr »

chas wrote:RTD PT1000 Type 501
PT1000 RTD Temp Sensor Chart.jpg
I think the "Type 501" designation is a particular manufacturers model number that was used as an example in this Wikipedia table. I do that think that applies to the la Spaz rtd's.

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AndyPanda

Re: What type is the coffee boiler temp sensor?

Post by AndyPanda »

Thanks for all that great info. However my machine does not have that tap on top of the boiler. Mine is a Mini Vivaldi II but it is an early one. My existing sensor looks exactly like the one at Chris Coffee (except black wires instead of white). My sensor works OK ... but I just notice that when I flush 2oz it is a good 10 seconds or longer before the heater kicks on. And when it finally notices the temp drop, it isn't just one degree -- it usually jumps to all of the LEDs going out and then gradually (one at a time) the LEDs light again until it's stable. So when it's heating up it comes up one LED at a time but after a flush it goes from all the lights on to suddenly all the lights off after 10 seconds of no reaction at all.

I usually work with K-Type thermocouples and what I notice with them is that when they come with the bead inside a sheath (like my sensor for the Vivaldi), it takes a long time for them to react due to the thermal mass of the metal sheath. So I usually remove the sheath and get the actual bead on what I want to measure and it reacts in a fraction of a second.

So the reason I was asking about the sensor was in the hopes I could find just the raw sensor (not embedded in epoxy and metal sheath) so I could put some thermal paste on it and push it into the well. I think that would react faster.

But if the original vivaldi and the vivaldi II both used the same sensor well --- why do all the brochures for the version II claim that it is all new sensor that sits directly in the water and reacts in half a second?

I'm wondering ... since my boiler doesn't have the spot on top for the newer sensor, perhaps my sensor is a version 1 sensor and it might be worth buying a new one from CC even though mine has not failed. But I'm still tempted to buy just the RTD sensor itself from an electronics supplier (like $4) and push that into my existing well with some thermal paste.
PT1000_RTD.jpg
PT1000_RTD.jpg (17.86 KiB) Viewed 13784 times
AndyPanda

Re: What type is the coffee boiler temp sensor?

Post by AndyPanda »

I read an old post (dream) where Chas had mounted a temp sensor in both places (on top of the boiler and also in the old position at the back of the boiler) and was going to test to see if there was a difference between using those two different locations. But I never saw a followup post on how the test went.

I'm wondering, since I don't have a spot on top of the boiler, how the new dream temp probe might work in my boiler mounted on the back.
AndyPanda

Re: What type is the coffee boiler temp sensor?

Post by AndyPanda »

Chris Coffee insists that the sensor from the Dream will not work on the Vivaldi - they claim that one is a TC and the other is an RTD ... I think they are wrong (but you would think CC would know).

Anyway ... my coffee boiler doesn't have the tap at the top like the one in the picture Chas posted earlier. But I decided to see what happens with the shorty sensor in the back position where the long sensor tube normally goes. I swapped the steam boiler sensor with the coffee boiler sensor. The advantage I noticed was that it was much quicker to notice a temp drop - I mean when I flush an oz or two, I see the LEDs respond faster and the heater kicks on. However it seems to be slower to shut off the heat on the way up - so it overshoots the temp by quite a bit. You can wait a bit and the overshoot cools down to where it should be - but it doesn't seem like an improvement so I'll swap the sensors back.

I'd be very tempted to drill and tap a spot for the sensor on the top of the boiler - but looking at Chas' picture, it looks like there is a welded in threaded lug. I wonder why it would need that vs just drilling and tapping a hole directly in the wall of the boiler without the lug? The walls of the boiler seem plenty thick. I suspect they moved to that location on the Dream because it's close to where the cold water comes in - and that should make it quick to respond when you turn on the pump.
Fcsteve777

Re: What type is the coffee boiler temp sensor?

Post by Fcsteve777 »

Just for some clarification, I'm having some issues with my machine and I compared the resistance of both temp sensors to see if they are close to the same.
They are not pt1000s, they measured at 165k and 228k ohms well outside of pt1000 range. And they also have a negative temperature coefficient (resistance goes down as temp goes up) which is also not a trait of RTD's.

They appear to be NYC Thermisters

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slo
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Re: What type is the coffee boiler temp sensor?

Post by slo »

I just measured the resistance of a brand new temperature sensor that I received from CC for the Vivaldi II, the new shorty type, and it measured at around 200K ohms at room temperature. I also confirm that the resistance decreases as the temperature increases.

I am no expert in temperature sensor, but it would seem that Fcsteve777 is correct and indeed the Temperature sensors on the Vivaldi II are likely to be NTC type thermistor.
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