Aprilaire Model 700 Automatic Whole-house Powered Humidifier with Digital Control

Spent many hours researching how to install a whole house humidifier and this one was recommended many times. When our furnace got serviced this fall the technician also recommended we get a humidifier and when I asked him which model this is the one he recommended. It's really hard to find anyone selling this unit because the manufacturer doesn't want just anyone to install it, they recommend a technician so I was pretty happy when I found it here on Amazon.

After doing some research and a couple times watching this video on youtube([...]) I decided to take the project on myself. It actually was a lot easier than I had expected. Aprilaire's instructions were pretty easy to follow and the automatic digital control gives you a great display in case an error code comes up.

If you are good at following instructions, and have some confidence you can save yourself around $300-$500 on the installation cost I was quoted from 4 different HVAC companies. I was able to complete the project in 3 hours. Another friend of mine installed the same unit in his house and he took just about the same amount of time, he might have been closer to 4 hours. So in 3-4 hours you will be sitting back enjoying the new humidifier.

Things You Will Need To Install Yourself:
* 3/4" PVC pipe (optional, i used it to run the 1/2" tubing into to continue to the drain instead of running the tubing all the way, I split into the same 3/4" coming out of the furnace)
* 1/4" copper tubing to run the hot water into the humidifier
* 1/2" plastic tubing to drain the water
* Sawzall or equivalent tool to cut sheet metal
* Low-Voltage wiring to wire the thermostat and thermometer (i bought 2 of these Coleman Cable 09631 CL2 Bulk Thermostat Cable, 18-Gauge 2-Conductor 50-Feet)
* 2 Electrical - Terminals for the wiring
* Some wiring caps (medium size)
* Foil Tape (I bought 3M 3311-50 Scotch Foil Tape, 2-Inch-by-50-Yard)
* Pipe Cutter (I bought Ridgid 40617 1/4-Inch to 1-1/8-Inch Close Quarters Tubing Cutter)
* Permanent marker
* Level

It's been running for over a month now and I was able to notice a difference immediately. I even have a gauge on the second floor that measures humidity and it's constantly has the correct amount of humidity in the house. I'm very happy with this purchase and highly recommend it to anyone in the market.

I had been researching whole house humidifiers for some time and finally decided on this Aprilaire Model 700 Automatic Whole-house Powered Humidifier with Digital Control from talking to local HVAC installers and reviews I located online. I checked around and the lowest I could find someone to install it for me was $350, so I decided to take the plunge and do it myself. I was a little apprehensive because I had never worked with a furnace or cutting into sheet metal before. I bought an inexpensive pair of sheet metal snippers and it was a little difficult, but not bad overall to cut the hole in the plenum. Home Depot proved to be invaluable in helping me with the plumbing connections. I used shark-bite fittings instead of the supplied saddle valve (every plumber I talked to advised me against using the saddle valve). I also used plastic pipe instead of copper. Overall I spent about $70 on supplies. I installed the unit on the supply side, as was recommended, but I could not justify hooking it into the hot water line and watch energy just pour down the drain. The instructions indicated a cold water supply was fine as long as the unit was mounted on the supply side. The unit does trickle water down the drain hose as it is operating, this is normal. My biggest apprehension was the wiring. I found some VERY helpful youtube videos of an HVAC installer somewhere in the midwest installing one of these in a clients home. I probably watched them 20 times during my own installation. One hiccup I encountered was after wiring everything according to the instructions, my unit powered on fine, but would come on when there was a call for heat, instead of waiting for the blower to come on. This made me extremely nervous as I didn't want water vapor blowing into the plenum before the blower was operating. A quick email to the youtube video publisher mentioned earlier confirmed my worry and he explained to wire the transformer into the HUM terminal neutral on the furnace board and to then use the power for the blower HEAT terminal for the power. The installation instructions made no mention of what is correct as to when the humidifer should come on, but for peace of mind, wiring as suggested by the HVAC installer was preferred. One additional step I took was to purchase some duct sealant that I then used to calk around the unit to seal off any gaps. I have already noticed a huge difference in the humidity level in our home, as we live in a very dry climate in SE Idaho. I was tired of spending money upon money buying table top humidifiers that required expensive filters or just broke down and were junk after a couple of years. This unit seems like it will meet my needs, I give it 5 stars and would encourage someone with general handy-man skills to go ahead and try installing, but to be prepared to ask questions if you get stuck.

Buyers Beware.

In the lower right-hand corner of the installer instruction sheet for the 700 & 700m is this note:

"The Model 700 is not suitable for installation on ducts with horizontal airflow. Performance will be reduced." This is an understatement; performance is horrible when mounted on a horizontal duct.

It appears that many HVAC dealers aren't aware of this limitation, and happily recommend it as "top-of-the-line." When installed horizontally, the Model 700's hard work at all--even with hot water supplied--and the dealer flounders around scratching his *** while you suffer from dry eyes, cracked skin, and static charges around the house.

There's a fascinating thread on this topic on the Professional HVAC forum. Just google "aprilaire 700 horizontal duct."

There were 5 main steps that I needed to do:
1. Run Electrical for outlet and transformer
2. Cut hole and hang humidifier
Note: I used a jigsaw to cut the hole. Also, my template was smaller than what was stated in the directions, so measured the unit and the direction size matched the size of the unit.
3. Add water line
4. Humidifier wiring
5. Add PVC pipe for water water hose to drain

It is working well now and took myself and a friend about 6 hours to install this includes time running to the hardware store for wiring, copper piping, pvc, jigsaw blades, etc.

I have gone through 3 humidifiers in 10 years. Was looking for something quality built and with the possibility of lasting more then 3 years. Checked for it on Amazon and selected this one. Then called few local HVAC places and the price including install was $600. Ordered it on Amazon and had it installed by local HVAC tech for $60.00. It took him 2 - 3 hours to do it but it has everything, including outside temp censer. Works like a charm and the tech suggested to change filter every 2 months due to the water conditions. Total cost was $306.00 installed. Easy to breath in home now.

Our house has been so comfortable since installing. It just feels so warm all the time and no more static electricity. I love the self temperature compensating controls.
I had a Honeywell 360 for 3-4 years but the electronics didn't hold up and it begin making the worst screaming buzzing racket.
Aprilaire makes the best humidifiers in my opinion. A friend got me a discount on the Honeywell. What was I thinking?

The unit arrived in just a couple days. I had a pro install it. Took a couple hours. Humidity in the house has been much better.
I tried one of the spray mister types last year. That was a mistake. This Aprilaire is the right answer even though a bit more expensive.

Positives:
Solid construction
Digital humidistat gives you actual humidity in home
Outdoor temp sensor adjusts humidity in home automatically

negatives:
Advanced DIY for install (Need plumbing, electrical, and sheet metal skills)
Connections to furnace can be tricky, especially in newer, advanced furnaces with communicating thermostats - the wiring diagram given would not work with my setup - had to talk with HVAC pro and decipher wiring diagrams from furnace maker website.

Overall, a great product - hire a pro if you're a novice DIY!

After reading reviews, I purchased and installed this product. The directions were good and installation was pretty much straight-forward, although somewhat time consuming if you're doing this yourself. After installation, I had a couple of questions concerning the wiring so I called the company and the tech service person was extremely helpful. It works well and definitely does it's job of keeping humidity at a comfortable level, not to mention that you're avoiding constantly replacing those filters every few weeks and re-filling every day.

I had Aprilaire 700 installed in November 2004. It worked fine for 1 year and then the problems started... the never ending problems that you invite upon yourself by purchasing this model. I wish that someone had warned me.

Pros:
1. It will work just fine for the first year or 2 years if you are lucky.

Cons:

1. The automatic sensing is unreliable. Too many components make troubleshooting a nightmare. Great if you are very technical and have the right equipments and tools for troubleshooting.

2. Major flaw - The inline strainer (little piece of cheap plastic that goes into the inlet side of solenoid valve) gets brittle, breaks and then gets stuck inside the solenoid valve. This causes 2 major problems. 1) If you are not very attentive, you will end up paying a lot of money for your water bill as the solenoid valve will start leaking due to this issue. 2) The broken piece will cause obstruction to water making the humidifier useless.

This is a major design flaw and the manufacturer should have mentioned specifically to replace the inline strainer every year - but they don't. They just mention about inspecting. Replacing Solenoid valve alone will cost you about $70 + labor extra!

3. Another major flaw if you have this installed on the hot water. The manufacturer should have recommended not using Saddle valve on hot water supply. Saddle valve will slowly accumulate sediments and close itself and you will spend hours trying to troubleshoot what is wrong.... that is if you notice that your humidifier is not putting out any humidity in the air. It will continue to consume electricity, run the fan and give you an illusion that everything is working just fine unless you are a good handyman who knows what to look for and if you have some kind of instrument to measure and detect that the humidity levels in your house have dropped. Unfortunately re-piercing the valve will only work once or twice until it blocks permanently and then replacing the valve is your only option.

If the installer has unfortunately installed saddle valve on hot water, then pay a plumber to install a different type of valve that would be more reliable. Of course, this will cost you $$$.

4. Feeding tube is not easy to replace. You can buy this part easily online, however, the replacement part does not have a good seal at the compression nut and you may end up with a leak.

5. If you have Radon problem in your basement, then this humidifier will suck that radon and distribute it throughout your entire house for free as it sucks the basement air.

As you may have already guessed, I had all these issues and I am frustrated with this humidifier. There are other humidifiers out there that will not consume so much water and still deliver great and reliable performance. I am planning on replacing mine soon.

While this is the larger of these and made for a larger house (ours is 1544 sq ft) it works great and mounted fine. One of the pieces didn't work when the HVAC technician went to install it but luckily he replaced it for free. Great for keeping a dry house humidified. Would have given 5 stars if everything worked when we got it.

I have an existing Aprilaire and was thinking I would replace that one with a newer model when I was having problems with the old unit turning on. I ordered the replacement and it arrived quickly and packed well. When I opened the outer box though, there is a tape seal over the inner box that says that if the product is not installed by a qualified HVAC service person it voids the warranty. That seems harsh, but after looking at the installation instructions I could kinda understand why. I had hoped that this would be a one for one swap with my old unit, but I couldn't tell if that would be the case without removing the old unit first. I decided to just return the unit to Amazon and managed to get the old unit working properly by cleaning out the water valve.