Fridge Thermostat Improvement project

[Jim_H42]

The freezer and fridge thermostats never did a good job at keeping the temperatures steady in my Passage 42. The fridge would freeze food even on the lowest setting (not to mention it used a lot of unnecessary energy). I found a $15 solution with an Inkbird 12V Dual-Stage Temperature Controller.
https://www.amazon.com/gp/product/B008KVGWT4/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1


For the installation, I leveraged the original thermostat wires making it easy to convert back to the original system if needed. I now can digitally dial in the desired temperature, variance and compressor delay. This gives the ability to make the freezer into an additional fridge if needed. Net/net this project was time and money well spent and is saving a lot of battery amps.

 

[Don Crowther]

nice fix
Would you care to tell us how much time and money?
Thanks

 

[Nodak7]

Jim, sounds like a good project.How about the make and model of the fridge and freezer?

 

[smokey73]

Can you sketch up a wiring diagram that shows how you "leveraged" the existing thermostat wire. I have the same problem with my freezer. I have a new ISOTHERM refrigerator so just need the single unit for the freezer. Thanks

 

[Jim_H42]

Don - the digital control (link in original post) was $15 which includes the temp sensor (I needed 2 controllers since the Passage 42 has separate freezer and fridge boxes). I spent an additional $10 for the enclose, wires and a couple connectors. It took about 2 hours to hook it all up – that was after about 3 hours of planning – my wire runs were easy to get at. The instructions that come with the controller are very poor, both in wiring the unit and programming it. I watched several YouTube videos to get ideas on how it works (homebrewers tend to use the 120v AC version of this device – but the hookup/configuration is the same with the 12v DC model).

Nodak7 – I have 2 old Adler / Barbour units – one for the fridge the other the freezer. I can't find the model so attached a picture.

Smokey – I drew something out and attached a picture (I can't figure out how to get the pic horizontal on the upload). The green/red line (which do not represent polarities) was the existing thermostat lines. Red/Green connected the original thermostat to the compressor. I cut red/green and hooked them up to the new controller. I connected the new temp sensor wire (which comes with the digital controller) to the existing wires in the box, leaving the original thermostat in place but not connected. Because I used the same type of wire connectors it’s easy to reconnect the original thermostat back in place. The only other thing necessary to get everything back to original is to reconnect the red/green wires and bypass the digital controller.

I should point out I attached the controller power supply to the compressor power – that way the controller turns off when the circuit breaker is off. The digital control retains the settings even with power disconnected.

Hope this helps. Jim

 

[richard9525]

Jim
Is the $15 thermostat still working normally.I saw that same thermostat on eBay also. I read some not so good reviews about that thermostat.Do you recommend that as a fix for temperature issues.

 

[Jim_H42]

Richard - I don't know the long-term reliability of this specific unit - but it has been working great for me non-stop for a month now (my solar works well here in sunny Florida I purposely wired it to easily convert back to the original setup if needed. The negative reviews I had seen on Amazon seemed to have come from people who didn't know what they had bought or how to hook it up. That said, this is a Chinese product and the instruction booklet is very lacking.

 

[Rich Stidger]

Jim_H42,
I bought a similar 12V temp controller but have not yet installed. Maybe this Spring I will get to it. I also have two A-B units and they cool a cold plate style of evaporator.

My question: The OEM mechanical thermostat uses a bulb that is clipped to the cold plate. It senses a temperature that is much colder than the box temperature. When you installed this electronic controller, did you attach the temp sensor to the cold plate or does it sense the box temperature? And if you did attach the new sensor to the cold plate, how did you get the readout to show the box temperature?

 

[Jim_H42]

Rich - My A-B units don't have cold plates - just the typical thin metal evaporator plates, so my temp sensing wire is zip-tied to center shelf of the box.

 

[Capt jgw]

I hooked the same thermostat to the fridge in my Columbia 36. I just unhooked the stock thermostat wire from the control box and connected it to the switch terminal on the Inkbird. Then ran another wire from the other switch terminal to where the stock 'stat connected. Very simple and I can still turn the unit off with the stock thermostat. Power for the Inkbird is tapped from the fridge power. If I want to revert back all I have to do is put the stat wire back where it was.
I've been using the 120V version on my beer fermenter for years, works great. As above the bad reviews were from people who couldn't figure out how to hook it up without instructions.