The climate in Utah is particularly arid, both in the summer and the winter, and so I had my builder install a Lennox whole-house humidifier as part of our HVAC system in the Utah house. It helps keep us feeling comfortable at lower temperatures, meaning we save money on heating.

The Lennox Healthy Climate HCWP3-18 humidifier we use is a “water pad” system, meaning that when our Ecobee WiFi thermostat calls for humidity, a solenoid valve on the humidifier opens and allows water to drip down through an expanded metal water pad, while a large fan blows the water droplets into the furnace duct, where the water vaporizes into the air that’s rushing up through the furnace and eventually out of the floor vents throughout the house. Here’s a photo of my humidifier with the fan housing removed:

Whole house humidifier with fan housing removed.

This Lennox unit been a reliable and effective way of increasing the humidity throughout the house, which not only makes us feel more comfortable but also helps leather, wood, and other “soft” materials wear better because they don’t dry out.

A couple of days ago, however, I was participating in a discussion on the Ecobee thermostat mailing list, and we started discussing whether it’s more effective to use hot water or cold water in this type of humidifier. The general consensus on the mailing list is that the hot water side is more effective, since vaporizing hot water is much easier than cold. A quick web search of humidifier manufacturer instructions confirmed it: it’s almost always preferable to use hot water in a water pad system.

And as Murphy’s law would have it, the plumber (or HVAC professional) who installed my unit plumbed it to the cold side. To make matters worse, he used a saddle valve to tap into the cold line to divert water to the humidifier. Saddle valves are no longer
“up to code” in a number of countries (including Canada), as well as more and more states in this country. They can clog easily, especially in states with hard water like Utah, and they are generally more prone to leaks… which is a bad thing in a vacation house that’s not lived in all the time.

So I saw this as an opportunity to do two plumbing projects in one sitting. First, I’d remove the old saddle valve from the cold side, cut out the piece of copper pipe that the saddle valve had pierce, and put in a proper T fitting, and install a permanent pressure gauge. I’ve always wanted a pressure gauge, for not other reason than I think they look cool.

Second, I’d tap into the hot water feed coming off the 2nd water heater, also using a proper T fitting, and connect a small shut off valve that feeds the humidifier water line. That way, I can shut off the water to the humidifier without having to shut off anything else, which will come in handy when I (inevitably) need to replace the humidifiers solenoid at some point in the future.

What really excited me about this project, however, is that I’d finally found an excuse to use what I think is one of the best advances in plumbing since flushing toilets: SharkBite fittings. If you’re unfamiliar with them, check them out the next time you’re at a hardware store. They make joining copper or CPVC pipe a breeze. No solder, no threads, no tools. Just slide in the pipe, and it’s connected and sealed.

I dropped by BJ Plumbing Supply in Orem, showed the guys photos of my current setup, and started gathering all the parts I’d need. The guys there are always friendly and helpful, and their prices are no higher than the big box stores — or even online sources I’ve found. If you have a local plumbing supply store, get to know the guys there. They will save you time and money, and are happy to pass along free advice.

Getting Started

Once I got home with all the parts, I started by shutting off the main water to the house:

Main water valve shut off

Next, I went into the utility room and snapped this “before” photo:

This is how the contractor installed the cold water feed to the humidifier

The pipe with the black tape wrapped around it is the cold water line. Following that pipe down in the direction of water flow, you can see the saddle valve that feeds the humidifier, followed by the shutoff valve for the inlet to the water heater, then the white expansion tank I recently replaced. The line then feeds into the first water heater (which does the majority of the heating) and then feeds warm water out of the first water heater into the the inlet on the second water heater, when then feeds hot water up through the pipe on the left side of the photo.

There’s a bathroom on the other side of the utility room wall, so I turned the sink faucet on cold and the shower faucet on hot, to help bleed pressure from the system. I turned both water heaters’ gas valves to PILOT, then then shut off the yellow-handled cold water  inlet valve feeding the first water heater, and used a hose to drain some water out of each water heater. Once the shower and faucet had both stopped running, I new that both the hot and cold sides were de-pressurized.

Cold Side First

I removed the 1/8″ compression fitting that fed into the humidifier from the existing saddle valve:

Existing saddle valve with 1/8″ compression fitting removed

Then I used a flat head screwdriver to remove the saddle valve from the cold water pipe. I had brought a brown Tupperware container and a towel to help catch any water, nothing dripped out when the valve was completely removed:

Cold water copper pipe with saddle valve removed

Having never used (or removed) a saddle valve before, I was surprised at how small the hole was. I decided that it could very easily get clogged with minerals or sediment, and made a silent vow to never use a saddle valve in any future projects!

With the saddle valve removed, I used a Pasco mini pipe cutter ($5 on Amazon) to make a clean cut just “downstream” of the saddle valve’s hole:

Yes, you can use a hacksaw, but a pipe cutter is preferable.

The main advantage of a pipe cutter over a hacksaw or a Sawz-All is that the cut is always clean, and the pipe stays perfectly round:

First cut done – and clean!

After a short learning curve on the first cut, the second one to remove about 2″ of pipe on the other side of the saddle valve hole was a snap:

Both pipe cuts completed.

The next part was what I’d been waiting for: installing the 3/4″ Shark Bite T fitting. It really was a simple as pulling the pipes apart (I have flexible copper on the water heater side, so making room was easy), attaching the fitting in the middle, and pushing inward on both pipes. At $20 each, they’re not super cheap, but they’re totally worth it. Not only are they easy to install, but you can re-use on other projects them later by taking them apart with cheap plastic tool that looks like an orange letter C. It seriously took about 12 seconds to push this baby into place:

My first Shark Bite fitting installed easily!

Next up was wrapping some Blue Monster Teflon tape around all the threads of the two bushings I needed to reduce the 3/4″ outlet of the Shark Bite fitting down to  1/4″ for the pressure gauge, and then screwing them all together:

Blue Monster Teflon tape is my new fav!

The final step for the cold side was to screw in the gauge, tighten it down. Because I had the shut off valve closed just “downstream” of  my new gauge, I decided to turn the houses main water back on so I could see if everything worked… without leaks. I panicked when I turned the house’s main water back on, because I immediately heard water gushing!

But then I remembered that I’d left turned the bathroom’s cold faucet open. Phew! Everything was working fine. No leaks anywhere, and the gauge was showing 60 PSI of water pressure:

Pressure gauge showing pressure… with no leaks!

Now for the Hot Side

Emboldened by my early success, I moved over to the hot side. First, I used my handy dandy pipe cutter to remove a 3″ section of copper pipe:

Hot side pipe cut, ready for the T fitting.

Then I put Blue Monster Teflon tape on all the reducing bushings and the new 1/8″ stainless hot water shutoff valve threads, and assembled them all into the Shark Bite T fitting:

All hot side fittings taped and assembled.

Installing this second Shark Bite fitting was just as easy as the first. Click, click, push!

Hot side fitting installed!

The final step was to connect the existing compression fitting from the humidifier’s copper feed to the new hot shutoff valve:

Hot water feed to humidifier connected!

I opened the inlet valve to the water heaters, crossed my fingers, and waited for a leak. It never came. Everything worked perfectly on the first try!

The “after” shot with new fittings, valve, and gauge installed.

I temporarily clicked up the humidity setting on my Ecobee WiFi thermostat using my smart phone, and waited to hear the humidifier kick on. After a few moments, it did… and I heard water flowing and felt the copper feed tube warm up. My humidifier was now using hot water!

Final Thoughts

So does the hot water feed to the humidifier really make that much difference? Honestly, it’s too early for me to tell. If it does, it’s probably minor, but it is technically the preferred way to do. If the previous install hadn’t been using a saddle valve, I may have been less motivated to go through the effort. But since replacing the saddle valve required pipe cutting anyway, I figured “why not?”.

One thing I did notice, however, is that the excess water flowing from the humidifier’s drain pipe is cold. That makes sense, since the the large fan blowing on the hot water is like blowing on hot soup to cool it off, and heat is transferred into the furnace’s airflow.

In total, this project took about 20 minutes, and cost me about $70 (2 x Shark Bite T fittings @ $20 each, $12 for the pressure gauge, $8 for the stainless angle valve, and another $10 in assorted brass bushings). And even if the hot water doesn’t make that much difference in humidity, it’s still worth the expense to eliminate a potentially troublesome saddle valve from the system.

As always, I welcome your comments, questions, and feedback below.

If you liked this post, you can also check out how I wired my Ecobee WiFi thermostat to my humidifier in this post, and if you want to monitor for leaks in your utility room (if you have a faulty saddle valve, for example), then you can also check how I connected a WaterBug water sensor to my Ecobee.