Crazy temperature spike

Hello everyone,

Although new to being an actual member, I’ve been visiting this forum for a while now. I’ve got my brewpi running with an Arduino Uno and RPi 2, which up until now has been working perfectly - good temp control to within +/- 0.6 degC, and super easy to program, thank you Elco!!

This morning I thought I’d check the temps, see how things were coming along, and I’m glad I did. Something very concerning happened, and my beer was practically back in the boiler again…! My IPA reached 80 degC!

Can anyone shed any light on how this happened? It’s scorched the bottom of the fridge, melted the airlock, and I don’t think the beer is going to be much good either… software crash perhaps? Any ideas would be greatly received.

Cheers, Adam

First of all, do not use a heater that powerful in a fridge.
Use something around 100W that is safe to run continuously. Using something like a 1000W heater in a fridge is a fire hazard, as you have clearly demonstrated.

Second: I am sure that it is not the software. The Arduino firmware has not changed in 2 years, because it is end of life.
What caused your heater to stay on continuously, I don’t know. Something hardware. But we stopped with Arduino 2 years ago, so I cannot help you with that, sorry.

Hi Elco,

Thanks for the reply. I should probably say that I wasn’t in no way pointing the finger here, what you’re doing is great, and even more so that you allow the software to be used free of charge. Sorry if you read my initial post as anything other than just me trying to work out what happened.

I totally understand the arduino is no longer supported, and when funds allow I will certainly upgrade from what I have at the moment. When is the next spark hardware expected? Are you aiming for a similar price point?

I guess that it must have been one of the power relays sticking that has caused the problem (they aren’t SSRs), so I’m going to change them out and also stick a thermostat in the line to the heater as a precautionary measure, to cut out if it ever happened again. Also, just to clarify, the heater is only 100W. I’m pretty surprised it did so much damage to the fridge!