Model 3000 Wire Extender (Adds Two Wires)

Great product. I used this to expand on a four-wire thermostat cable so that a common wire was created and humidification could be controlled from a smart thermostat as opposed to having to go to the basement to adjust the humidifier setting. I wanted to run a seven conductor thermostat wire, but I couldn't get the existing wire to budge and found a fire block right below the hole in the wall where the thermostat was; I didn't want to risk running another wire and losing the existing one, nor did I want to punch a bunch of new holes to do this.In all, the Fast Stat 3000 took about 20 minutes to wire into the system completely at both the furnace and the thermostat - but admittedly, I have spent some time installing the thermostat at this point so I'm getting very familiar with wiring. Also helpful was that the hole behind my thermostat is very large (an electrical wiring box size) and easily accommodated the sender unit, which was smaller than I expected given the pictures. My only advice is to take your time, be methodical with performing the connections, and write down what you did at the furnace so you can refer back to it while wiring the thermostat. Also note that when you power up the thermostat for the first time, the thermostat may not be able to detect the new wiring given the diodes in the sender unit. You will likely have to update the wiring configuration manually after install - again, no big deal.So, what would have made this 5 stars? I would have liked to seen more diagrams in the instructions that would have explained a few more scenarios on how to expand the wiring when starting with 4 wire systems as opposed to a 2 wire system. In my case, that would have made this a slam dunk purchase with a thermostat as running a new wire was absolutely not in the cards. I had to go through a few iterations on how to do this before deciding to purchase this product.Other than that, I would easily recommend this product to others.

Excellent solution to my A/C needs. I have a three wire heating system with the old mercury bulb thermostat. I added A/C and the new wireless digital thermostat, so needed two more wires (Common for powering the thermostat and Cooling). This FAST-STAT Model 3000 was the perfect solution. Easy to install and works perfectly. So glad I didn't have to pull a new wire bundle because I wasn't up to putting holes in my basement walls and ceiling.

As stated by another reviewer, would be great to have the instruction sheet shipped with product available online. My case (convert HVAC with gas furnace+ac, using a 3 wire to a 5 wire to work with a nest) was included in printed instructions, but not online.Apart from that, has worked like a charm-nest believes the equipment is 5 wire with common, r, y, w and g.

Easy to install and solve an otherwise costly problem of not having enough wires.