🔍 Improved SEO: Johnson Controls A421ABC-02C A421 Series Electronic Temperature Control, -40°F to 212°F Range, SPDT Review

Ideal for heating a beer fermenter. Well-made, durable, reliable, worry-free. The instructions were a bit hullah, but after playing with the controls a bit it became clearer to understand, and then it got better. I will definitely buy this again.

I use this to convert my chest freezer into a kegerator and it works great. It keeps the temperature within 2 degrees of what I set. I haven't had any problems with it so far. It's a bit more expensive than other controllers, but definitely worth the money.

The new A421 is a major improvement over the A419. There is now an on/off setpoint and a permanently on backlight. I welcome these changes. For people familiar with the layout and use of the A419, this will work just fine. I'm using this to revitalize an old bar fridge that had analog controls that no longer worked. Since the fridge is good, that saved it from a landfill. It came with a pre-installed power cord and was ready to use right out of the box. Fast delivery from the beverage factory.

I use a third controller for my fridge that will tell you something. However, every replacement I order has been updated and improved and lasts longer than the previous one. It has a large digital display. A good thick rubber spool? or plastic? kind. Continuous. Very easy to use even without knowledge of electronics. Keeps my chest temperature exactly in the selected range. The simplicity, affordability and extremely low power consumption of the entire system (temperature controller plus…

Bought 2 in February this year for 2 keezer, the settings are the same, one does not work the other. Although the screen works, it does not turn on the device, even if the indicator light shows that the device is on. Contact seller said that the warranty period has expired, offered to contact the manufacturer, I ask him to indicate the manufacturer's contact, I have not received an answer, I am still looking for the manufacturer. most likely another brand will do. Seller/Manufacturer, if you…

this is my second controller. The first is used to convert the freezer into a refrigerator. It works great and I can still use it as a freezer just by turning the dial. The second unit is a cheap standing refrigerator with a temperamental temperature controller. When you bought the refrigerator, it had a lot of setting options, which led to large temperature fluctuations in the compartment. This control allows me to adjust the high/low range exactly how I want it. The instructions are a little…

Bought to control a submerged heating cable in a workshop floor drain. The pipe was frozen below 20F. The device is really versatile. It is fitted with an external remote temperature sensor to control the on/off set points which are fully programmable. Can be used for heating or cooling (but NOT both - it only has one relay). The temperature sensor cannot be submerged in water, but is moderately splash-proof when installed correctly. The display shows the current sensor temperature. Units of…

I had this A421 controller not long ago but it was easy to set up and works as it should. I use it to switch the heating tape on and off in my camper trailer. I wanted something very reliable, even if it costs many times more than those cheap candles with some sort of thermostat inside. It looks like these cheap things can burn out and I don't need a fire hazard or frozen water lines. There are fancier versions of this controller that have more features. I think you can factor in the…