Emerson Thermostats 1E78-140 Non-Programmable Heat Only Thermostat for Single-Stage Systems, White

I love this heat only thermostat. It is easy to install and instructions are great. Even when the display is not illuminated the display is large and easy to read even for me with bad eyes. The display is so much better then the Honeywell rh110b that it replaces, which has a monochrome like display where the numbers are almost the same shade as the background and does not have a light. This is a perfect choice if you have just two wires, white and red used for forced hot water hydronic heat with an oil boiler. You also have to clip one of the jumpers on the circuit board that makes your boiler react correctly using hot water heat. The construction is also better then the Honeywell and easier to use. This replaces the old round Honeywell that had a twist dial and mercury switch which I used to have some years back. Update 11/14/19: I have put in to return this thermostat and get a new one. The flame Icon doesn't turn on when the thermostat calls for heat, it stays on all the time so I don't know if it's defective. I believe it comes on when you select a temp that is higher than the room temp and shows it's talking to boiler to get heat. So I am returning to see if it is defective. Update 11/18/19: I have received a replacement thermostat and installed it. The thermostat performed the same as the last one. I have found that once you turn the switch from off to heat, the flame icon stays on until you turn the thermostat off. The flame icon has nothing to do with the heater status. I sent a question to Emerson and have not got a response about the function of the flame icon. I am moving my rating to five stars as the thermostat is functioning properly and is a quality product that does exactly what it is supposed to do. I do hear a click as I raise the temperature above the room temperature, so I believe it functions just fine and keeps the temperature right at set temp. Update: I did not clip the 905 jumper as it suggests and this keeps room temp right at set temp without overshooting the set temp. It is very easy to clip the jumper if you decide to.

Very easy to install for a heat only system. Works exactly as it should now my furnace will work more efficiently. Very durable construction that is compatible for my heat only system. With a low price point. Compatible and controls are easy to use. +++++ product

Works perfectly even on a Millivolt system( floor furnace ). I love the digital control over my last Honeywell thermostat. The temperature stays constant now hence no need to be playing with the thermostat setting all day! The Honeywell thermostat I had was flawed I think intentionally to sell more thermostats because no engineer in their right mind would design a thermostat with set of contacts that suffer from bi-metal corrosion increasing the resistance which made it fail just slightly after one year of usage! Just a heads up, when you buy your thermostat, test the relay contact resistance before installing! The standard resistance reading for this particular thermostat should fall between 0.3 - 0.4Ω. Some people are selling used thermostats and taking advantage of unsuspecting buyers! I've tested some that measured between 2 - 7Ω and that means the relay contacts are corroded and not making a good enough connection to even work with a millivolt system. Here's how you test your 'new' thermostat to see if it is actually new and that you haven't been scammed! Just grab a digital millimeter and set it to OHM and install two temporary wires onto the two screw terminals on the right hand side of the thermostat. Make sure you solder the ends of the stripped wire to keep them from corroding which insures the lowest resistance reading possible! Flip the thermostat switch into "HEAT" mode and install the batteries. The thermostat should now be powered on and displaying a temperature. Next, increase temperature setting till you hear the relay click closed. Now make your measurement across the two wires you just installed and if reading is higher than 0.3 - 0.4Ω then box it back up, return it for a replacement or refund. Also, if you have to make a wire splice on a millivolt system because you're existing thermostat wires don't reach the screw terminals. Solder all your new connections together to achieve the lowest resistance possible especially if you're dealing with a millivolt system. If you're still having issues then I'd advise you to check the amount of millivolts the thermopile is putting out! Even a new thermostat would solve the problems that a weak thermopile or pilot flame issue causes so just be aware of that fact before you go blaming it on the thermostat. Hope that helps and good luck with your repair.

We are using this thermostat with our gas steam furnace and it is simple to use and understand. The on-off switch is mechanical and is reliable. If you need to change the battery, you just pull the thermostat box straight out, away from the base, like pulling out a plug from an electric sock. There's no screws and no plastic latches to lift or press... easy, peasy. However, the digital temperature control is electronic and has a minor flaw that reminds us of the old days of using Windows 3.1. In the middle of winter, six months after we installed the thermostat, the temperature setting became "frozen" and wouldn't respond to the up or down buttons. Fortunately, there was no blue screen of death and the thermostat would still regulate the room temperature. We just couldn't change the room temperature setting. Also, like Windows 3.1, we found online that there was a way to fix this problem and it involves pulling out the batteries for 5 minutes, then sticking everything back together, causing the thermostat to reset. Due to t problem, I took away just one star. I am used to working with electronics and it is an easy fix. However, thermostats are supposed to be more reliable and I can certainly understand if someone took away all of the stars over this flaw. Meanwhile, I bought a replacement thermostat in case this problem keeps happening.

Quick upgrade for Travel Lite truck camper thermostat. Original was VERY difficult to switch on or off. This replacement has three simple buttons - On/Off, and Up and Down to set your desired temperature. An added feature that I really love, is that the digital screen I am sorry shows you the temperature inside, before you ever turn on the furnace. The unit itself has two AA batteries so the digital screen is self powered and does not drain your house battery. (A similar digital temp gauge I have runs years on two batteries.) Once you turn the furnace on, the screen will show you your set temperature and the current inside temperature. Do yourself a favor - skip those replacement thermostats with lever switches and get this digital Emerson. Install took five minutes and a phillips head screwdriver, just two wires.

Perfect for my Grooming van. Swapped out older analog for this newer digital. You connect either wire to RH and W and remove the wire bridge. I had to read reviews to figure this out because directions are sucky. Same would apply for any older unit with only 2 wires for a propane heater in their rig. Works great otherwise

This product changed my mind about digital thermostats. I always liked bimetal spring based thermostats before trying this one. After all, those are passive, no batteries required, and they work on physics principles. What could go wrong? The answer is plenty! The one in my RV had sticky contacts. What I mean is the electrical contacts seemed to stick together. That resulted in a terrible problem, which the digital thermostat has solved completely. The problem was the temperature would have to drop way below the setpoint to get the furnace to turn on. Then, when on, the temperature would have to rise way above the setpoint before the furnace would turn off. This was awful. In a small RV there was no consistency in the temperature at all. It would swing widely above and below the desired setting. Plus the temperature control only had two options, ie warmer or cooler -- no actual temperature selection. This digital thermostat is absolutely one of the best upgrades I have ever done to my RV. I can select whatever temperature I want and the thermostat will control the furnace precisely. The variance is only plus or minus about 1 degree. I am thrilled with this precise control. This is saving propane, which saves me money. Plus, I love the backlight. Now I can see the temperature and the setpoint even in the middle of the night. This digital thermostat runs on two AAA batteries. I put Energizer Ultimate Lithiums in it. Those should last 2-5 years before needing replacement, they never corrode, and they are imperviousness to temperature variations. This inexpensive digital thermostat is an excellent upgrade for an RV and it has changed my opinion of digital thermostats in general. I strongly recommend this, especially if you have an old analogue thermostat in your RV.

Very nice unit. Replaced my analog unit with this one. Works perfectly.

Excellent product

J’ai installé ce thermostat dans ma roulotte. Fonctionne très bien et quand même assez précis. Fini les grands écarts de température.

Over the last few years I've had a difficult time with my regular wall switch being used on my millivolt gas fireplace continually requiring replacement. Decided it was finally time to purchase the right type of switch to replace with the builder head installed. I found this to be very easy to install and works very well, plus the thermostat helps me ensure that I'm not inadvertently leaving the fireplace on too long but it's no longer needed. Item was well packaged, instructions for clear and it looks well built. I expect this to last. The only criticism would be is that you have to cut a wire on the circuit board in order to change the display from Fahrenheit to Celsius. The downside is that changing it back would require soldering. Overall I'd recommend.

My house has an old (as in 60+ years old) hydronic boiler heating system with millivolt controls. Over the years I've replaced the thermostat twice before and now my thermostat was giving me trouble, so I decided to replace it. All the 3 different models of thermostats we've had over the years, none has been able to keep the temperature inside our house constant. After reading reviews of several products, I decided to get this thermostat. Installation was easy but the instructions aren't great (hence the 4 stars instead of 5). When I installed it, I connected the black and white wires, and I cut two jumpers as per the instructions: (1) jumper W904 to change the display to degrees C, and (2) jumper W905 to tell the thermostat the heating system was hydronic. Installation took less than 10 minutes. The thermostat has now been installed for a week. During this week the temperature outside has varied from +4 °C to -21 °C yet the temperature inside our house has been constant at its setting of 21 °C. Keeping the temperature constant was something none of our previous thermostats could do with our heating system. I can't speak about the thermostat's suitability for other types of heating systems but for an old hydronic boiler system, this thermostat seems perfect! Update: After 2 years the thermostat still controls the temperature properly but the temperature increase/decrease buttons have stopped working. Consequently, I've downgraded my rating from 5 stars to 4 stars.

My electrician installed this model with my home rewiring over 8 years ago. It has never failed, I've only replaced the batteries twice. When one of the batteries leaked, I had to buy a new one. I went looking for the exact same model. I found it here on Amazon.ca. (Thank God Emerson kept this model in production after the merge with White Rodgers.) I love that it shows the temperature in Farenheit. I can see it so easily, thanks to the backlight function (which you have to turn on - thank you to the Amazon customers who gave simple instructions on how to do that!), the display uses large figures, very nice, so easy to install I did it myself, and accurate! I love the accuracy! When the first one had been installed, I had been using a dial thermostat for over 40 years. I was surprised any thermostat could be so accurate. Is it any wonder I went in search of the exact same model?