HoneywellHome RLV3120A1005 Digital Non-Programmable Thermostat for Electric Heat Only

I did not fully appreciate what this thing would do for me. My circumstances were that my old Cadet baseboard heater made metal popping noises when the heater went on or off, because I had the original on/off controller from about 38 years ago. (There was also a problem unique to my house, of the gypsum board emitting cracking noises with thermal changes... possibly due to a second layer of board being put on the ceilings to cover a '70s-style popcorn ceiling.)Perhaps the later Cadet heaters don't make the metal popping noises, as I see that they have a special flexible mechanical mounting to prevent that. Anyway, the point is that THIS IS A PROPORTIONAL CONTROL thermostat. That means that it's not on/off. It could, say, operate at 40% power and then if the temperature outside drops it might kick up to 42% power.That it virtually never causes the heater to operate at maximum power means that electrical cords in outlets above the heater--- they are now against code--- never get hot. In my case, the heater is now never hot enough to damage anything, let alone ignite it.And so that's also why I no longer hear ANY thermally-induced noises due to the heater.Note that this is a 2-wire device which usually means that it's suitable for 120 V operation, not 240. However, it is rated for 240 too and you can use it for that. However, current codes where you are at may require that you use a 2-pole, 4-wire device such as Honeywell TL7235A1003 Line Volt Pro Non-Programmable Digital Thermostat with Electronic Temperature Control, 240-Volt.It's possible to become confused. If you are replacing an old thermostat and it has 4 wires coming out of the back, that is the most proper setup for 240 V, 2-phase. So if you defeat that by putting in this 2-wire device you have to join together two wires from one side of the 4-wire device that you are replacing and only connect the other two to this device.Do not be confused by the 4-wire diagram in the instruction sheet. It is not inapplicable to this device with 120V. It does not particularly refer to a 240-volt setup and if you have 120 V it instead depicts the situation when the electrician ran the wires from the breaker box to the thermostat box on the wall before routing them to the heater, instead of the other way. With that arrangement you will find a jumble of wires in the box on the wall. Just pull out the two that are attached to the existing controller and replace the old controller with the new. It doesn't matter which wire from your new thermostat goes to which wire in the box on the wall, as long as you attach them to the two that were previously attached to the old thermostat.It's so delightful to walk into the room to find the temperature pegged at exactly the set point. Better sleeping.

The Honewell RLV3120A1005/H is an extremely simple thermostat for two wire baseboard heaters. You set the temperature, and it holds it there until you decide to come back and change it again.I’m replacing an old Swan manual thermostat from the 60’s. It was a simple On/Off thermostat which worked off an expanding piece of metal. Accuracy was not its strong point as my room went from feeling like Antarctica to Guam in less than a half hour if I tried to set it to a measly 70 degrees. The heater was either on full blast or turned off. This made my room feel very stuffy and overly warm. There’s probably a reason for that but I’m no heating expert.I would have liked to get a programmable model but I didn’t want to spend too much (I’m renting the house from the college after all) so I settled on the Honeywell. Looked to do all I needed it to anyway.The thermostat feels pretty substantial. Upon opening it up you’ll find a large heat sync and some beefy circuitry to handle the baseboard heater. It’s rated for 1000 watts at 120 volts and 2000 watts at 240 volts. That’s a roughly 7 to 9-foot heater. The exterior plastic feels solid too. The buttons are very clicky but don’t have a very satisfying travel.Installing was a piece of cake. It has black two wires coming out the back, roughly 4-5 inches long which you connect to the baseboard heater wires in your wall. Color and order don’t matter. The box includes wire nuts for securing your connection and two screws for attaching the device to the wall. After killing the breaker (always cut the power to your heater before installing these things) I wrapped the wires together, used the nuts to secure the connection, carefully replaced them into the wall box, and screwed the thermostat in. The screws that come with the thermostat are very long and didn’t fit my wall box so I used the ones that secured the previous thermostat. Once it was secured to my wall, I slipped the top plate over the thermostat and switched the power back on. Worked like a charm.Operation is stupid simple. The display always shows the ambient temperature. Clicking the up or down keys once shows the temperature setting. Clicking them again changes the setting to the desired temperature. Clicking both keys at once brings up a setting to change from Celsius to Fahrenheit. When the heater is on the thermostat will display 1-5 little flame icons. The thermostat will throttle the heater to keep energy use to a minimum and make sure your room doesn’t get turned into an oven for the sake of a single degree. The flame icons indicate how intense the heater is running with five being blazing hot and one being warm to the touch. This throttling works great and the temperature is kept within around +/- 1 degree most of the time. When on full intensity, the thermostat can get a little warm to the touch (guess that’s why it has a heat sync), but not enough to worry about.Pros and Cons!Pros:• Super easy to use• Setup is super easy, just two wires!• Display is easy to read and clear. No noticeable fade from different angles.• Runs heater at optimal intensity for smooth heating and lower power bills• Stays accurate to setting• Does not click when turning on or offCons:• Buttons are plastic and don’t feel all that great to press (nitpicking, they are fine)• Buttons on my unit feel slanted to the left. They are tilted away from you with a noticeable angle that you can feel when you press them. Weird design choice in my opinion so maybe it’s a defect? (Also nitpicking, they are fine)• There is pretty much no other functionality other than adjusting the set temperature (which is fine because that’s what it is)• The screws were very long and didn’t fit in my wall box so I had to use the screws from my old thermostat. Not a huge deal either but a little annoying.My heater is a simple 7 foot two wire electric baseboard heater with no forced air.Overall, this is a fantastic unit. If you are looking for a simple thermostat to run your baseboard heater then pick up the Honeywell RLV3120A1005/H

In my room heated by radiant ceiling panels, this keeps it within a range of 5 degrees Fahrenheit. This is a really wide range, and seems to be because the thermostat is not smart enough to understand the delay between when it adjusts the power and when the air at the thermostat changes temperature. And that's a shame, because it has the ability to apply varying power to the heater, using solid state electronics, so it should be able to maintain a nice constant temperature within a degree, running at fairly continuous power.In a differently heated room, it might do much better.It's great that it has the variable power, and displays the current power level (as from 0 to 5 heat wave icons).It displays the temperature it senses, but only with 1 degree F or .5 degrees C precision. It certainly measures it more finely and probably uses those measurements internally, but I would like to see more precision on the display.The user interface is easy enough when you know how to use it, but could be more friendly to first time users. The unlabeled buttons are "raise set point" and "lower set point" and the first time you press either one, it just displays the current set point, along with a dot that is supposed to let you know you're now looking at the set point and not the actual temperature. After 5 seconds, the dot goes off and you go back to the actual temperature. If you don't remember how to switch between Celsius and Fahrenheit, you'll have to locate a copy of the instructions. There are no instructions of any kind written on the device.

just as it should afterall its made by Honeywell