Finally, a digital thermostat for my oil fired boiler! If you have an oil fired hot water boiler and radiant floor heat then this product is for you. What you'll likely find out is that these systems use 'line voltage' and not 'low voltage' as many oil furnace systems use. I'm pretty handy around the house, and I thought I was pretty well educated on home thermostats. Oil furnaces and boilers all use low voltage to run a thermostat, right? Well, nooooooo, they don't. I was surprised to learn that after buying a plain old digital thermostat to replace my analog dial mercury switch. Pretty much every thermostat at a big box retailer is going to be low voltage because that's the most common. When I stuck one of those on my wall it did pretty much nothing (and may have gotten damaged in the process, though thankfully there were no whips of smoke billowing out). So, I pulled out my voltage meter and did a quick check and found out, "holy crap this is 120v AC." Hence began my internet search for a 120v thermostat. Come to find out, the 120v, or 'line voltage' system isn't too common. I wasn't able to find many thermostats that would fit my application, and many were specifically for electric baseboard heating. A bit more research brought me to the Lux ELV4. Finally, I had found what I was looking for. This is a very solid piece of hardware, and priced pretty competitively with low voltage models (though being more common they are generally cheaper). The ELV4 provides separate programming for weekday and weekend use. You can set two morning temps and two evening temps which generally cover 'wake up', 'go to work', 'return from work', and 'go to bed'. The clock display can also be set to show 12 or 24 hours. I have no doubt that the precise control of this unit will far exceed the performance of the old mercury switch (which most building codes don't allow for these days anyway). I'm going to watch my oil bill, but I'm betting I'll be spending less now that we can more finely control the temperature in the home and avoid the 'thermostat tennis' habit. So with all the great features, I wish there was one thing that could have been included - a back-light. You're going to have to turn on your room or hallway light if you want to see the display in the dark. A darn shame since that's really the only nit I have with the unit. I would give my review 4.5 stars if possible, but since I have to choose 4 or 5 I'll still go 5 because the rest of the unit is so solid. Finally, a word of advise, READ THE DIRECTIONS when you install. Yes, the wiring is pretty obvious (line voltage 'in' is red and 'load' out is black), but there are a couple things that can bite you if you don't RTDT. Obviously, there is a front panel that flips down to allow you to get to the programming options. What is NOT so obvious is that the face of the unit separates from the back mounting plate and there are MORE options BEHIND the face of the unit. Specifically, there is an on/off switch for the heat which can be used during the summer when you don't want the unit to turn on at all. The thermostat is shipped with the switch in the OFF position, so if you don't turn it ON you may think you have a DOA thermostat. Also, there are two 'dip' switches on the back to set the temp to either Fahrenheit or Celsius, as well as for the 12 or 24 hour clock. I'm attaching a picture of the thermostat with the optional trim plate (sold separately) for your viewing pleasure. Happy heating!
