Temperature Sensor Failed, but now appears fine

Over the weekend while I was out of town I was Cold crashing 2 starters and had the fridge set to 38 F. I had 3 temp connections, 1 room temp, 1 chamber and 1 labeled beer. The beer one was sitting on the bottom of the chamber since this was a starter.

Saturday morning the temperature rose to ~120 F. When I got home Sunday night the Chamber Temp on the BrewPi was reading --, the beer temp is how I know the internal temp of the bridge. I unplugged the brewpi, pulled the starter out and went to bed. Today I plugged it back in and all appears to be operating normally.

I am assuming one of the temperature sensors is going bad. Any other ideas?

BrewPi Photon 0.4.2


If I have identified you correctly by your e-mail, you did not buy our sensors but got them elsewhere, correct?

The sensors you can find on eBay/Amazon are not really waterproof can water can seep in and damage them when you put them directly in the beer. Ours sensors are really a different level than the ones wrapped with shrink wrap that you can find in other stores.

BrewPi should not heat though when it loses the fridge sensor. Did it? Can you share a chart?


The 3 temperature sensor’s where purchased from the BrewPi store. They are your Silicone RJ-45 models.

I am wondering if it’s a power issue. I ordered a new 12V 2AMP wall adapter for the Photon. That should alleviate any issues with power.

I will send a chart when I get back to the network where the device is !!

Brett Starter Cold Crash.csv (90.0 KB)

Quick question about temp sensors, since I am interested in avoiding probe failure. I am using 1 meter DS18B20 probes from Amazon: (http://www.amazon.com/gp/product/B00IYE4X70?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00). The product specs say it’s accurate to 0.5 deg C and precision of 0.0625 deg C (12 bit, although I got that info from another site about DS18B20 sensors.)

First off, I didn’t know about the shrink wrap not being great at keeping the water out. Thanks for that info! I currently have my probe in a carboy of water for testing. I was planning on using a thermowell for the beer but I am thinking twice using the probe that’s been soaking in water the past week. I don’t want it to fail on my first fermentation with my BrewPi. Second, if we get the BrewPi store probes, have you seen any better performance out of them in terms of accuracy and precision?

The sensor inside is the same (DS18B20), the difference is the quality of the cable, probe and sealing.

Under the shrink wrap is usually a blob of glue. It can dissolve. Not sure it will happen in water. Cut one open and see how crappy the ‘water proofing’ is.