Experts Guide on How to Install a Whole House Humidifier

        Have you considered whether you need a humidifier in your home? Do you know how to install a whole house humidifier? As the weather reminds us that winter is coming, the air will become drier. As we run the heaters in our homes, it will continue to dry the air out even more.

Overly dry air can cause sinus issues, cracked lips, dry skin, and can even cause wooden furniture to shrink and crack, causing damage. A popular solution to all of this is installing a whole house humidifier. It will run with your furnace as it helps to humidify your air. In this article we will explain to you how to install a whole house humidifier. 

Getting started: Planning the installation

The first thing you will want to do is locate the templates with your humidifier. The humidifier should have given you a template for the hole where the humidifier will be mounted and a smaller template for where the humidistat will be mounted.

Find the desired location where you would like the humidifier to be mounted. Be sure that there is at least six inches above the humidifier to be able to mount the humidistat. This may not be easy with the other HVAC components around.

You will want to make sure that you know where the drain will be going. This is another thing to consider in the placement of your humidifier. You will need to be able to easily remove the cover and filter pads for easy maintenance and repair.

You will also need to consider the bypass pipe. This will be a six-inch pipe that travels from your humidifier to your supply duct. When planning where you want the humidifier, you will also need to plan around this. It should ideally be as straight and short as possible. When you are sure of its location, take a felt-tipped pen and mark out the future holes where the humidifier and humidistat will be mounted.

Once the holes have been marked, you will want to drill a hole in all four corners of each one. Make sure that the holes are large enough to get sheet metal snips started. Right or left-handed sheet metal snips tend to work best for this type of application. Now you will be left with a hole for your humidifier, and a hole for your humidistat.

Mounting and setting up your humidifier

         Once you have the holes cut you will want to mount the base of the humidistat over the hole that you made. You will then want to remove the cover and pad from the humidifier and mount the base over its respective hole. This will require one-inch-long sheet metal screws. Make sure that you mount it using the supplied holes only.

         Next, you will want to mark out a six-inch hole in the supply duct where you are planning to connect your bypass line. Take your drill and start a hole at one edge, and then use your snips to cut the circle out. After this, mount a starting collar over the hole and secure it with ½” sheet metal screws. If necessary, attach your elbow to the starting collar, and measure to your humidifier. If you need any more fittings, try to have those in place first, as it will be easiest to measure a straight section. Once your pieces are cut you will fit them together, attach them with three screws per connecting joint, and then use foil tape to wrap the joint and seal it from leaking.

         You will want to plumb in your drain next. If you have an air conditioning system or a high-efficiency furnace, then you should already have ¾” PVC as a drain. If so, that will make the drain portion quite easy. This should allow you to plumb the drain from the humidifier to the drainpipe. If you do not have a drainpipe, you may have the option to run it into a laundry drain, floor drain, or pump near the unit. Whenever connecting your pvc be sure to always use PVC-specific glue.

How to do the Wiring

         If your humidifier came with a step-down transformer, then you will want to install it next. It is vitally important to shut the power off to your furnace at this point. You will want to see if you have a HUM on your furnace circuit board. If so, you will want to take the wires from your transformer, place the power wire from the transformer on the HUM, take the second wire, and place it on NEUTRAL. The black wire will go to HUM and white will go to NEUTRAL, but it is best to check your instructions to be sure.

How should the wiring be connected? You will have a wire that runs from one of the other two wires on your transformer carrying twenty-four volts to your humidistat. Then a wire will go from the other side of your humidistat to your humidifier. It will run back to your transformer from your humidifier, making a complete loop.

If you choose to do your wiring yourself, you will need to ensure multiple things. Ensure the wire is not rubbing any sharp edges, that a sheathing protects, that it is secured and out of harm’s way, and that you have good connections. If there are wire nuts, make sure they are snug and all the wires are not moving. If it is a spade connecter, to connect to the circuit board, make sure the crimp is tight, and there is no wiggling.

Connecting to a water line

         You will be given a saddle tap in your humidifier kit. This will be a couple of pieces of metal with bolts on both ends to squeeze the water line, and a piercing valve in the middle. Find the nearest set of water lines; ideally you will want to utilize the warm-water side. If the water line is plastic, such as PVC, PEX, or CPVC, then the piercing tool will pierce it. The same should go for copper piping.

         You will want to make sure that you have your line run and hooked to the humidifier first and to your valve once it is clamped in place. Make sure that your new water line is tucked out of harm’s way. With the plastic and copper types of pipes, screw the piercing valve all the way in to pierce the pipe, and then back out. This will allow the water to flow through the pipe to your humidifier.

  If you have a steel pipe, you will have to shut your water off and open a valve at the lowest place in your home to try and relieve the pressure. Then you will have to use a small drill bit to drill a hole in the pipe. After that you will have to line the hole up with your piercing valve and tighten the clamps to seal it. Then run your water line and turn your water back on.

Final Steps

         Now that you’re almost done, put the screen back in the humidifier, put the covers back on your humidifier and humidistat, and then you are ready to test it out. You just installed a whole house humidifier!

You can turn the power back on to your furnace and turn your humidistat to test. Once your furnace kicks on, you should hear a click from your humidifier within a couple of minutes. That will be the solenoid coming on, to start the humidification process. And the sound of a job well done. And that is how you install a whole house humidifier.

         There are multiple hazardous steps in this process, if you do not feel comfortable with the process of how to install a whole house humidifier by yourself, then call a professional. It is always best to leave it to installation experts like Clover who know what factors should be considered. 

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