Honeywell RLV4305A1000/E 5-2 Day Programmable Thermostat for Electric Baseboard Heaters

Pros:- very easy to install.- designed to do to what it does: help you program your heater and save power/money for heating.- it pays itself based on my heat uses after 1 to 2 years.Cons:- screen is very small- not very intuitive program setting, you need to read into the manual a bit to understand itOverall, a very solid product at its price range. A very smart choice if you do not want to spend hundreds on smart home products.

I have been using this thermostat now for about a month. If you have the skill to change an in wall light switch, you can install this thermostat. I use mine to control an oil filled roll around type radiator style space heater. You cannot use this thermostat, or any other external thermostat if your heating unit has a built in electronic control. Manual contols only! (switches & turnable more or less heat knob).This thermostat is completely quiet, fairly easy to enter settings, (read the instruction sheet until you understand) and controls room temperature within a degree. The room temperature showing on the display is not as accurate as the temperature control cirquit, and is an unimportant aspect of this very accurate controller. Want dead on RTD type reading? Triple the cost of this thermostat! Mine reads 2 degrees high. So I set it at 70 instead of 68°. What is important is the industrial accuracy RTD tyle lab calibration temperature sensor on my night stand.(I'm a retired Energy Management/Automation controls Engineer with 38 years experience) This thermostat works very well.15 second cyle, 15 minute cycle? Fan, no fan? This thermostat uses one or the other methods to control the electric heating element. The 15 minute cycle is used with heaters that also have fans in them. It runs for upwards of 15 minutes and cycles off to maintain the temperature. The 15 second cycle only controls the heating element. It uses a solid state switch (triac) to pulse the heat element on or off to closely ccontrol the room temperature. At near setpoint, this unit pulses power at 1 second on, 14 seconds off. If the room is way below setpoint, the heater will be on continuosly untill the room temperature approaches the setpoint, then starts by pulsing 14 seconds on, 1 second off, all the way to completely off at setpoint. This is standard electric heating (no fan) control with much higher accuracy. Been around for 30 plus years, but very expensive untill the past few years. This kind of pulsing is harmless to heater elements.I used a shallow surface mount wall box, surface mount wire/cable wall guides (2), mounted box 5 feet above a wall outlet, used a 20 foot round, 3 prong extention cord. I cut the extension cord long enough to push the male (the part that plugs into the wall) up into the wall box, then pushed the remaing cable up the second channel guide into the wall box, connected the two white wires together and used appropriately sized twist caps. Connected the thermostat wires to each individual black extension cord wires. Thermostat is not polarized. Mount the thermostat to the wall box. Plug the extension cord from one of the cable guides into the wall outlet, the socket end of the extension cord is for the room heater male plug. Turn the heater switch(s) to high, heat knob to max.Many oil filled heaters cannot reject enough heat on high without overheating the unit! So manufacturers put overheat cutoffs to cycle the element off until it cools. JUST GREAT! This derates the heater from 5200 btu's to about 3000, maybe. That 1500 watt heater is really 800/900 watts. The specs. are on paper only. Solution: A 7 inch metal cage, fully rotatable 3 speed table fan. 1 programable timer. Place the fan on a side of the heater, angle it up towards the upper portion of the oil filled heater. Plug the fan into the timer, the timer into another wall outlet. Match the timer schedule to the thermostats schedule. The heater can now output all its heat indefinately. One on/off cycle should be adequate. Clean the fan on a regular basis. DO NOT CONNECT ALL FOUR BLACK WIRES TOGETHER AS ONE BIG TWISTED CONNECTION.Reader assumes ALL liabilities! How I did mine, and posting on Amazon reviews, is not to be taken as an instruction or direction on how to install, wire, or use this product with an electric heater. If you are not well versed in electrical theory and application, consult someone who is.

Easy to install, but instructions not the greatest.Worth buying to help reduce heating bills by automatically controlling heat settings.

This review is for the "new" version, RLV4305A.I got this to control a 1200W Electric Radiant Cove Heater (QMark RCC12012C) that I installed to provide supplementary heat in a bedroom. For this project, a programmable thermostat was a requirement. If I let this radiant heater run continuously, it could cost me over $100/month in electricity, just to improve the heat in one room which I am mostly not in during the day.It really is silent. The box says it uses a TRIAC, which I learned is like a dimmer. So instead of clicking off when the room gets noticeably warm and clicking back on when it gets noticeably cold, this t-stat constantly raises and lowers the dimming level to tightly track the setpoint. There is some indication of this in the display, showing 0-5 heat wave squiggles, depending on how much power it allows through.The LCD display lights up when you press a button and stays lit for 10 seconds or so. Normally, it is completely dark. Without the backlight, it is still readable if there is enough ambient light, like during the day or with room lighting on. In normal use, it displays the current time and temp, mode and period, plus the squiggles mentioned above. Touching the temp up/down button once will show the set temp.Install is straight-forward if you are familiar with household electric service.This device is installed in series with the electric heater (like a wall switch) and modulates the line-voltage AC electricity that actually passes through both the thermostat and the heater(s). There are no low-voltage control lines here like a regular household thermostat has.I don't understand why there are 4 mounting holes in the unit. I used the 2 left holes with the 2 included screws to mount it to the left half of a 2-gang electrical box. I don't get why the other 2 right holes don't line up with the holes on the right side of the box, but even like this, it is plenty firm and secure and it completely covers the box opening.Programming is easy."5-2" means you set separate Mon-Fri and Sat-Sun schedules, but nothing more sophisticated. By default, the M-F weekday schedule has 4 time periods (wake, leave, return, sleep) to program, but the Sat-Sun schedule only has 2 (wake, sleep). However, you can set times and temps for the 2 other Sat-Sun periods (leave, return) too. If you have a weird schedule you want to program, this might not be sufficient, but for most cases this should be good enough and easier to program.There are enough buttons with meaningful labels to make the work of programming it fairly easy. Rotate though the 8 periods with the "pgm" button, and change the time with the hr/min buttons and the temp with the up/down buttons. Finish/save by pressing the "⏎" button. Not rocket science.There is no "OFF" button or mode. "Manual" mode is a constant set temp like an old thermostat. The "Away" mode allows for a lower constant set temp (default 59f), presumably for extended time away from home. "Standby" mode is almost OFF, but it will turn on if the temp drops below 41f. In all the modes, it draws a tiny bit of power for itself.I have not tested this unit during an extended power outage, but it claims to remember the date/time for 5 hours or so without power. There is no battery compartment, so it must have something like a rechargeable battery or a big capacitor inside it.I'm very happy with the quality and the price is better than every other programmable line voltage thermostat that I've seen.

There aren't a lot of affordable, programmable high-voltage thermostats. This one is nicely designed, easy to physically install (programming is a different story) and does a great job. I installed two of them, one for each floor of a building that uses 240V radiant ceiling heat, and both floors are perfectly controlled now.The only downside: I had to call their tech support people for programming help. Over the course of several decades as an electrical engineer and part-time electrician I've installed at least 100 programmable thermostats and timers for gas and electric heaters, swimming pools and spas, irrigation systems, blah blah ... and this is the first time I couldn't program one either intuitively or using the manual.Even with help from a very cool, English-speaking French-Canadian Honeywell technician residing in Mexico, it took awhile for the two of us to figure it all out. Now that I know the secrets, I have no qualms about using these for any 110/120/220/240V application.