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Problem with a419 dig. thermostat

Hi, I have a few of the a419 dig thermostats from NB, and the most recently bought one is behaving poorly. Any suggestions on where to go for this.

I noticed that it defaults to BIN setting, which should require me to wire the top of 3 screws and unwire one of the others, which of course I have never done and isn’t currently wired anyway. It stays in BIN no matter what I do with the jumpers.

That said, assuming I set the offset for this mode to 1, I should still have considerable control over temperature ranges (using with a lizard heater pad and carboy insulation). however, on every fermentation I have used this one on, it lets the temperature slide well below its set range and offset (it is properly set to heat/cut in 1 degree below range set). I have tested this back to back with another a419 between 2 separate fermenters, and it is definitely the thermostat as the other one, when put in place of it, acts just fine. The other one isn’t erroneously defaulted to BIN, but once again, with the offset set properly as per the manual, it should still be possible. Every setting besides the Temperature itself is set to 1.

The oddity is that when it is letting the temperature slide without limit, it still shows green light on (e.g. power on to connected device).

The first time I used this thermostat was last week and it has not worked properly for any sustained period (e.g. more than a day).

Am I missing something or does this sound like a defective thermostat?

I have three and they all work great for me with the “lizard heater”. Can you explain your issue again, please? I couldn’t follow your description.

I have mine set to a differential of 1 and all the other settings are to default (except for the monitored temp itself, of course).

Mine is, shortly after power-up, defaulting to BIN, e.g. temperature offset mode. In theory, this should use the OFS setting as part of its calculus of acceptable temperature range. Mine is set to 1. DIF is set to 1. The same settings (without BIN) work fine on other thermostats.

While the circuit has the green light for open, the lizard heater continuously loses vs. ambiental temperature when this thermostat is attached. I have felt the wraparound, and there is some heat coming from it. Nonetheless, it falls (10 degrees before I moved things around) without limit, yet once I change thermostats, the same heating equipment takes the fv back to set temp range.

The thermometer part itself is working right; when I replaced it, the new one showed the same (low) temperature.

My take is that it is defective, given the erroneous BIN setting and then the odd inability to actually regulate the temperature.

Did a simple test with the temperture turning on a simple on-off device. when it turned it on, it sparked the external device on for a second and then let it shut off, despite the green light still being on.

The thermostat is defective, will see what the return policy is.

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