800 Whole-House Steam Humidifier, Automatic Steam Humidifier, Large Capacity Whole-House Humidifier for Homes up to 10,300 Sq. Ft., White

I read many reviews on this both good and bad before purchasing. I spoke with a handyman about helping me install one, he said Aprilaire is a good brand. After comparing EVERYTHING, I decided on The Aprilaire 800, glad I did. Shipping was super quick. We live in Utah and winters are brutal, near zero humidity and my wife has a serious problem with low humidity. Overall, installing the unit was not complicated, but it took us 4 hours to run the electrical wire, and about 4 hours to install the system. Installing the Electrical It took us several hours to run the 220V line from the basement to the top floor, but we did it without tearing up the house. We had to consolidate two smaller breakers to free up a space for the new 220 breaker. We ran the wire from the break box into the ceiling and upstairs through the walls. From the floor in the furnace room (two floors up), we ran flex conduit from the floor directly into the unit and connected the wire through the conduit to the unit. Installing the Main Unit First, we mounted the unit to the wall and hooked up the 220 power. Next we tapped into the cold water feed above the water heater by installing a copper "T" and a new valve and connected the unit water feed. Next we tapped into the the drain line for the A/C by installing a PVC "T" and connected the unit drain line. Finally, we drilled a hole in the side of the furnace outflow duct above the furnace, and inserted and mounted the steam jet into the duct, then connected the steam line from the unit. Installing the Controller You have to install the humidistat controller on an inflow duct as that's where it measures the humidity. Luckily, there is an intake vent on the opposite side of the wall so we mounted the humidistat controller on the wall inside the furnace room about 6 feet from the furnace. We drilled a hole in the drywall and through the metal duct, and mounted the humidistat controller over the hole. Next, we connected the wiring from the humidistat controller to the main unit. Next, we connected the second wiring from the humidistat controller to the furnace. We had a little trouble figuring out how to connect the wiring from the controller to the furnace to get it to operate the way we wanted, but with a little persistence and two of us reading the manuals, we finally figured it out (we wanted the humidifier to operate the furnace fan by itself and independently instead of only operating when the furnace is running - there are several configurable operating options). Operating the Unit We installed the filter/heater cartridge into the main and fired it up. The unit ran through the test cycle, filled with water, drained, made some noises and turned indicator lights on and off, but when it finished the test cycle, nothing happened. We thought we had done something wrong, but based on the way we had configured it, the Aprilaire unit will wait for an hour to start up the furnace fan unless it comes on by itself. You can preempt that by turning on the furnace fan manually for a few seconds. Once its running, it will control the fan itself. So you have to either wait for the furnace to run by itself in order to trigger the unit to operate, or you can force it on by turning on the furnace fan manually. We turned on the furnace fan which triggered the unit to start up, so we shut off the furnace fan, and the Aprilaire unit turned it back on by itself. Within less than a minute, we could feel some heat through the steam line so we knew it was working. My house is 2 stories about 2,800 ft sq. The temperature outside was about 10 F (-12 C), we keep our inside temperature at 78 F (25.5 C). The humidity was 4% before we turned on the system. The humidistat controller has a range from 0 to 7, we set it on 4. It took the system about 6 hours to bring the humidity up to 30% and we could feel the humidity in the house, it was great. The unit shut off at about 38% humidity, so we cranked it up to number 6. We ran the system all night, and when we woke up, it was 66%. It felt like Florida in mid-summer, oh yah!. Many of the windows were fogged up on the inside, some had water all over the window sills. OK, we went a little crazy, 66% is too high. We don't run the system at night after we go to bed anymore because the air is cool coming out of the ducts when it's just the humidity running, so we crank it up before bedtime to about 55%, and then shut it off. The humidity by morning is usually around 35% to 40% and we keep the house around 35% and 40% during the day until just before bed. We've been using this since September, it's now March (7 months). We couldn't be happier with this system. I bought a spare filter/heater cartridge in case ours stopped working, but so far, we have not used it. This thing automatically fills and purges the filter once in a while (not sure exactly how often it does it), but so far we've had this running pretty much all winter, and it has worked flawlessly.

I went through two Honeywell Truesteam units before switching to the Aprilaire 800. The design of the Aprilaire is superior to the design of the Honeywell. It's really night and day. The Honeywell ran incredibly hot, and the circuitry is immediately above where the water boils (i.e., in a very hot place), and the parts are not near the quality of the Apriliare. Please trust me on this--the Honeywell is a toy compared to the Aprilaire. To be fair, the Honeywell only hooked up to 110 volt power, whereas the Aprilaire can hook up to 110 or 220 volts (another sign of a good design, BTW) as well as 11.5 or 16.5 amps. I have the Aprilaire hooked up to 220 at 11.5 amps and man does it work quick. It's amazingly fast. I've had it hooked up for three weeks now and it has easily kept the relative humidity at a near constant 45%. I ended up hooking it up to the Honeywell TrueIAQ humidistat that I already had installed, and everything is working beautifully. The Honeywell continually had issues, and I had to deal with them every single day until I just couldn't get it working anymore. The Aprilaire has had zero issues and I simply let it run. I don't take it for granted because I was trained by the Honeywell to check on it multiple times a day. Now whenever I check on the Aprilaire I do it with a smile on my face because it's always working exactly as it should. I'm so much more confident with this device because of the design. The other thing the Aprilaire handles well is that it works with either hard or soft water--each have their own pros and cons, whereas the Honeywell has to have soft water if you want to get any longevity out of it. I happen to have a water softener so this wasn't an issue with me, but I point it out because the Aprilaire is well designed even in this respect. If you have hard water you will replace the inner cannister more, but your unit will work well because the water will boil more efficiently. I should also note that my unit is a remote installation. It is installed in my linen closet about 6 feet away from my furnace. Even the hose that takes the steam from the unit to the furnace is superior when compared to the Honeywell. I haven't had any issue with the remote installation. When I first installed it and tested it, my humidistat was reading 45%, so I set humidity at 50% and it took only 40 minutes to get my entire 2000 square foot home up to 50%. I know it's not a big home, but it would've taken the Honeywell a lot, lot longer to make a 5% move. I'm telling you, it's night and day with this device compared to the Honeywell. Do not buy the Honeywell. Please. Look on the Internet by comparing the two and you'll see a lot of bad words for the Honeywell, including at least one of the reviews here at Amazon. Don't make the same mistake I made.

I purchased this humidifier for a newly-constructed house in January, 2015. My wife and I wanted to avoid the large shifts in relative humidity that occur indoors during the winter months in our area. I wired it to use a 240v dedicated circuit because of its higher output capacity. The installation was a piece of cake, since it required only a simple water supply connection and the addition of a 240v circuit. Since I did all the electrical for the house (and had it inspected), this was well within my skill set. I don’t necessarily recommend a DIY install, however. More about that later… The system is paired with a Honeywell thermostat and interface unit that allows control from anywhere in the world. I chose this arrangement because it can be programmed to automatically alert us to a variety of HVAC issues. We’re VERY happy with the performance of the humidifier. We set the humidity to 40% for the winter. During the summer months, we switch the system off, since normal activities like cooking, showering, etc. keep the humidity at around 35-40%. (Prior to installation, the humidity in the house had been hovering around 19% in January.) The system worked flawlessly for what remained of the 2014/2015 heating season and for the entire 2015/2016 heating season. However, when I powered it up again in October of 2016, it had what is called a “fill fault,” meaning that the solenoid that controls the water level in the tank wasn’t shutting off when the tank was full. By doing a bit of research online, I determined the cause to be a faulty circuit board. Since the humidifier was still under warranty, I contacted Aprilaire to arrange for a replacement. A friendly tech rep confirmed my suspicions about the probable cause of the fill fault. However, I learned that Aprilaire has a policy that all warranty work must be accomplished through the original seller. In my case, that was Amazon—I purchased it directly from Amazon, not from a third party. I contacted Amazon, only to be told that they don’t do warranty replacements. I explained what Aprilaire told me, but got nowhere. The rep told me that since I was beyond the return period, there was nothing they could do. He repeated the same words about the return period so often that I believe it must be a company mantra. I sent an email to Aprilaire about the trouble I was having, and offered to send the circuit board directly to them for testing. Because of what I think is poor wording in the warranty language about DIY installations, I told them I thought the part should be replaced no matter who had installed the humidifier. The fact that the system worked well for 1½ heating seasons indicated to me that I hadn’t done anything to cause the failure. After some back and forth, Aprilaire came thorough to my satisfaction, even though I initially purchased a replacement board from an HVAC contractor. Lessons learned: • Amazon isn’t set up to do warranty repairs or replacements—at least for this product. As of the day of this review, there is still a link to a file containing the back page of the owners manual that explains what is covered by the warranty. The language is still unclear when it comes to DIY installations. This implies that one will have a warranty to fall back on if something breaks down in the first 5 years. • Aprilaire has a FAQ section on its website that expressly states that all installations must be performed by a licensed contractor. Its warranty says that defects resulting from failure to use a contractor are not covered—not quite the same thing. • If you’re willing to take the risk of a failure occurring during the first 5 years, it doesn’t matter where you purchase this product, or who installs it. Depending on what you would have to pay for a licensed contractor to do the installation, you might come out ahead even if a part fails. • Aprilaire sells its products through HVAC contractors to ensure trouble-free use. I don’t fault them for that, or for requiring warranty service to be performed by the contractors. Unfortunately, they can’t prevent Amazon and other companies from purchasing and reselling their products. The friendly folks in Customer Service have spoken with Amazon about their policies concerning warranty work, etc., but to no avail. I don’t like it when reviewers say, “Don’t buy this!” or “Buy this from someone else!” Amazon does a great job in most cases. However, in this situation, I was not impressed. I received a follow-up email after my call, and it did nothing to help with my problem. At the bottom was a line that read as follows: “Your feedback is helping us build the Earth’s Most Customer-Centric Company.” There’s quite a bit of room for improvement on that one.

This replaced my Honeywell Truesteam (hereafter, TS) unit which was nothing but trouble. Because I already had the water, electrical, and drain for that unit the Aprilaire install was brief (2 hours). If you don't have all that in place, it's a good all-day weekend project, though it is only warrantied (and probably only truly safe) if done by a professional installer. I am not that. I'm a software guy but didn't have any trouble. The construction of the unit is orders of magnitude more simple, robust, and elegant compared to the plastic thing I had before. It's an all metal case with removeable front (end user access) and side (electrical access) panels. Leave yourself some room on the right hand side for access (manual says 16 inches, that's way more than enough). My only concern at this point is that our municipal water is not very hard - it's a 4 on their scale. So far I haven't gotten it over 6 amps without adding salt to the intake tank. If your water doesn't have a lot of mineral content you are limited on how much conductivity it has and the amount of voltage you're supplying (unless it steps up internally, not sure). In my case I'm going to get it hardwired to 220V by an electrician in the hopes the higher voltage will let it get closer to capacity. None of this is an issue for the TS because it uses heating coils, not electrodes, to heat the water. When it needs service (scaled up or worn out) the entire heating section (tank, electrodes, and water sensor) gets replaced as a single cartridge unit. That's sort of like replacing the imaging unit in a printer when it only needs toner, but it keeps it simple and the cartridges are not that pricey. In a sense they've made that part of the unit disposable so that the -whole- thing isn't disposable. I found the Honeywell TS units to be largely disposable on their own annually. If you have a scale filter and your water isn't very hard, try without the filter. Do NOT use a humidifier filter that contains an additive, as it will contaminate the electrodes and prevent full operation, possibly spoiling the cartridge. If it were able to run at full capacity without me worrying about mineral content (you can remove minerals easily but not add them) it'd be a 5-star unit. If the 220V mode gets me there, I will revise the review. I also see it's the top seller in the Steam Shower section. No idea if it's even approved for that, but it gives you a sense of the amount of steam that it'll kick out when really rolling. The TS steam was usually foggy, but if you disconnect the discharge hose the steam coming out of this is most clear until it hits something, so it must be hotter. Probably better for atomization into the airstream. The humidistat is pretty basic - the TS unit was a little more advanced, although I prefer this one. This has an analog dial but the guts are all digital and the LCD display is continually backlit with a blue LED which is very nice. On the older digital one I replaced you had to hit a button first to see what's going on. The display of the humidity is also about an inch tall vs the tiny 1/4" display, so if you're over 40 you'll appreciate that. The control wires to the humidifier are only a single pair (HUM+, HUM-). The humidistat in turn controls the furnace and turns on the fan and so on, which is different than the TS setup where the humidifier itself ran the show and the humidistat just displayed and controlled humidity calls. The humidistat in turn is the piece that receives the 24V transformer power and the incoming fan call signal and outputs the fan call on to the furnace if either your thermostat or the humidistat demands it. The discharge tube that goes into the air duct is metal, not plastic like the TS. It's also longer (about 7 inches) and has multiple discharge "tubelets" and apparently some internal design so that condensed water is returned to the hose, if I read the manual correctly. They includes most everything - clamps, hoses, and water tap. They really ought to include discharge hose insulation, as they call for it and the manual indicates better performance and more output with it. I had to steal my old insulation from the Honeywell I'm throwing out; I'm not sure if it was included with that unit or why I had some, but it didn't come with the Aprilaire.

First off installation instructions leave much to be desired. Second. The unit requires a water pump of good quality to pump out drain water. Third, even at 240V and low amps this thing DOUBLED (yes. That is correct. Doubled) my electric bill at the recommended mid setting. I can't even imagine what this thing would suck up in KWH on 115V. It is a power hog. My house is 5,000 sqft, and even after running it for a month, I never got above 32 % RH downstairs and less than 26% upstairs. The system was installed by my HVAC service company and they stated to me that I would be better off with an Aprilair 700. It would be much more energy friendly. I have a hot air system with multiple zone flapper controllers for balancing and on demand heat. Needless to say i had the unit returned. I will look to get an Aprilair 700 during the 2026 fall season. I am not back to my ultrasonic unit in my bedroom which is more capable of getting the room to 40% RH.

I have had the AprilAire 800 Whole-House Steam Humidifier in my house for over 9 years and it does a nice job. Mine died with what looks like a dead steam solonoid relay. I replaced the whole unit with a new one from Amazon. While the old one was somewhat noisy in that the water inlet valve could be heard closing on my old one, the new one was very loud. I called AprilAire support and was told that the noise comes from water hammer as the inlet valve closed. They recommended their 4280 Aprilaire Shock Arrestor which I saw being sold on the internet by distributors for over $120. I found a water hammoer arrestor on Amazon (https://www.amazon.com/dp/B01N34QEIU) which did a nice job of eliminating the noise. It has to be mounted with the tube facing up to trap the air which acts as a cushion to soften the noise.

While humidity is up, it is not consistent and doesn’t reach and maintain 40% humidity. It’s not as efficient as advertised and very expensive for the results.

Don’t waste your time trying to save money with a bypass humidifier sold at hardware stores. If you have a 2-stage heat pump, the supply temps are too low for a bypass to produce enough evaporation. And bypass only runs with heat, so those won’t humidify if it’s dry and already warm in the house. This can also be installed in the return side, if you have a 2 zone system, or no room on the supply side at all. I installed this myself, but have some apprentice level experience with HVAC and electric. This unit has options for electric, 120, 208, 240 and 11amp or 16 amp. The more voltage, more amps, the higher the steam output. Of course you need wire and a breaker to match that power level. It comes with a basic controller, but I have an ecobee 4 thermostat. This specific Aprilaire unit needs 2 wires(the pins for one wire option are physically missing on this model #) . To wire the ecobee 4, I installed their PEK (power extender kit) to free up 1 wire, and disconnected the w2 (second stage aux heat). If second stage aux is needed, then a relay can be used instead. Also, ecobee defaults to 5% over humidify. I set that to 2, to reduce window sweat and runtime. Ecobee has 2 options, fixed humidity % and “frost control”. I’d recommend “frost control” and then use the “window efficiency” setting to adjust. Once set right, The ecobee will adjust % humidity to keep your windows from fogging, in all outdoor temps automatically. The included Aprilaire controller, will have to be adjusted frequently, to prevent window sweat. Ecobee 3’s are free from my power company now and the 4 just adds Alexa if you were wondering. They will control the Aprilaire the same. Not included in the kit is 10/2 wire, breaker, disconnect, wire clamps, wire nuts, water pipe (ice maker kit size), water hammer arrestor, nor an in-line water filter if you need one(well water). If you don’t have central air ducts, Aprilaire does make a stand alone kit. Basically this unit with a wall register/fan box. So you can humidify a house with baseboard heat. Two points to note, 1. the solenoid doesn’t have an arrestor, either use stainless braided ice maker line, or copper and a water hammer arrestor. Due to the design, it won’t start hammering until 24-36 hours after the Hvac guy leaves. 2. The first 24-36 hours are low output. This is a steam unit, but instead of a heater coil, it’s an electrolysis plate. Plates last longer between cleanings, but take time to build mineral conductivity necessary for steam. For the impatient You can add a pinch of table salt to the canister to jump start that process. From a water consumption estimate, it appears to use 20-25 gallons per day, maybe 12-17 as steam. Much better than bypass models. From an electric consumption, it’s high as expected, 240v 17amps. Past 24 hours Outdoor temp of 25F, runtime ~6 hours, $2.58. From my TED pro Energy meter. But you have to factor in the cost reduction of using less aux heat. I set the ecobee to not run aux heat unless it’s 3F off, since this humidifier makes it feel warmer. And I set the ecobee not to run aux heat unless stage 1 has run for an hour, and stage 2 for the second hour. Also, prevent aux heat over 40F outdoor temps. With this steam unit, the effect is feeling warm, the heat pump runs much longer on a lower stage, and saves some money overall. Gas is completely different than heat pumps, so different tuning would be used. With gas, you’d probably have a bypass humidifier, unless it’s a large leaky house. With gas, it runs less often so just make sure to set the fan to circulate 10-15 minutes every hour. Otherwise the humidity will be unbalanced. And you may want to have 60 seconds extra fan time after the steam stops.