Temperature control

I want to do temp control on two FVs with a Lindr AS-40 (two lines). When connected (havn’t bought it yet) I understand that the temperature will be set and then a pump will recirculate. That obviously won’t work, because I need it to recirculate only when the fermenting wort is too hot. I can see a couple solutions. Put an inkbird in front of everything. That will turn the cooler off with the pump, and I cannot control the two strings separately. I can also separate the pump and cooler and use the ink bird only on the cooler. This still only gives me one temperature to control after. Then comes the brewpi related ones. I can either start the pump always and use valves to shut off the flow for each FV, potentially turning off the pump with a 240v relay in front of the pump.

Thoughts? Specifically wrt hardware and setup for a the new brewpi hardware.


We typically solve this use case with the Logic Actuator block.
Here, the valves would be under PID temperature control, with the pump activating if any valve is open.

That makes sense. Do you sell the valves also? I cannot seem to find any on the website.

I have a Lindr as-80.

The built-in pump is separately controlled from the compressor on my Lindr. You could let Brewblox toggle it and also control 2 valves.

I use the built-in pump for my taps (2 beer lines with cooled python).

I have 2 small 12V pumps that control the temperature of my fermenters.

I just leave my Lindr at about 4 degrees with the built-in thermostat. Brewblox just controls the 2 pumps that pump water through the cooling coils. It’s the simplest solution and it works well. No valves.

What should I look for when looking for 12V pumps? I always have a feeling that I don’t know what to look for or even where to look.

I don’t own a spark 3 so I am eagerly awaiting the new hardware to get on with this project btw :slight_smile:

New hardware is now available!
This pump is great for circulating glycol:

You can control it directly with 4 pins of the I/O module.


Great, thanks, and thanks for the pump link. For some reason I did not find it earlier, but when I search for pump I see it is there.

That was not your fault, it was misconfigured to not be included in search results.

Okay, great. So the plan is to use the spark as a controller for the two pumps. I have the lindr standing between the two fermenters. So I would need

1 x Brewblox Spark 4 - Featured products
1 x power supply?
2 x 12V immersable pump (for cooling with glycol)
2 x Waterproof OneWire Temperature Sensor (RJ11, DS18B20), extra long cable - Featured products

1 x server (I have that already)

Some extra wire for the pumps to connect to the spark (they look very short on the picture at least)


Yes, they are very short. You can use the 2x1mm wire cable that we sell, but almost anything will do.
I can include something to connect the cables to the pump in a waterproof way.

You’ll need a 12V power supply that you connect to the power input on the IO board. The pluggable terminal block is included, so you just need something that puts 12V on 2 wires.

I assume you already have thermowells for the sensors.

I have two fermenters with thermal wells and a lindr as20 yes. So I need the pumps and everything needed to connect it and control it.

Is it correct that all I need besides the stuff I linked above is 1) a 12 volt power supply (the one in the webshop is not in stock), 2) some wire and 3) some sort of way of extending the pump cables in a water proof way? (how?)