It’s that time of year again; you’re likely neck-deep into heating season, and I hope it’s going well for you! However, let’s face it, it could always be better. So, what can you do to ensure your next boiler installation is top-notch and trouble-free? Here are a few tips to keep those evil callbacks at bay!

One of the first things is to ensure that you’re filling your system to the right pressure. Trust me when I say it’s not always 12 pounds/square inch (psi). The static pressure of your system will depend on the vertical height of your piping in the application. While 12 psi is the default for a typical two-story home, you should understand why.

Let’s assume the boiler is in the basement of the building or home and that’s where you’re filling from and confirming pressure. From the bottom, you’ll need 0.433 psi/foot of vertical height to ensure you’ll even get water to the top of the system. In a typical two-story home, this is roughly 7 psi when read at the bottom of the system. 

While this gets water to the top of the system, it doesn’t guarantee pressure up there. In this case, 7 psi at the bottom of a two-story home means you’ve got 0 psi at the top.

This is why 12 psi is the default in those two-story applications. It takes 7 psi to get to the top but the extra 5 psi gives you positive pressure to make sure your air vents and bleeders work at the top of the system and any air can be pushed out. So, measure the height, multiply by 0.433 and add five for that little safety factor.

You may also need minimum pressure at the boiler to keep it operational. This number may be higher than what’s needed for the system, so keep that in mind. Also, be sure to set the air charge of your expansion tank to match your static pressure. Do this while there is no pressure on the waterside, as it can influence your reading and set up your piping to “pump away” from the expansion tank. 

By pumping away, your circulator is adding its energy to the static pressure instead of subtracting. Pumping into your expansion makes it possible to put parts of your system into a negative pressure, allowing air to be sucked in through air vents and other points.

Speaking of air, here’s another tip for you. After you’ve filled and purged, you will want to get your system circulating and up to temperature as quickly as possible for as long as you can while you’re there. You want to bring the system up to design supply water temperatures and, if needed, override or disable the boiler’s outdoor reset controls. 

On a mild day, your boiler control may only call for 140 F, but on the coldest day of the year, 180 F. Get it to 180 F regardless of what the outdoor temperature is.

The reason for this is because gases are less soluble in water as the temperature increases. By getting the system temperature up, you’re allowing your air separator to pick out those microbubbles and do its job more efficiently. This will reduce the potential for an unhappy customer and a callback due to an airlocked zone in a recently installed system! 

To be honest, I’ve always loved listening to an air separator whisper (psst!) on the startup of a new heating system and I’m sure you’d agree.

Manage Customer Expectations

Now, after you’ve avoided millions of other potential pitfalls, there’s one last thing, and it’s something you must do before you ever install anything! You need to avoid unrealistic expectations from your customers. This scenario may vary based on your location and your customer. 

For instance, hydronic heating isn’t as common in the Midwest and building owners/homeowners may not be as knowledgeable, so their expectations may need some fine-tuning. 

For example, I worked on a new construction home for a couple that was being built as their dream retirement home and in-floor heating was a big splurge for them. They had it in their minds (unbeknownst to the salesman or me) that the floors would be warm to the touch all the time, and it was never dispelled. 

A short while after moving in, the weather started to turn, and the heating started to run. It maintained temps and was running great except for one thing; the floors weren’t warm. 

This customer called and demanded warm floors. I voiced my concerns and tried to correct the situation, but the customer knew I could set minimum floor temperatures on the thermostat. Coincidentally, the day after my visit, I got a call saying the floors were warm, but the house was 83 degrees! 

The homeowners learned that if your floors are warm enough for your little piggy toes, there’s a good chance you’re putting too much heat into the home with 2x6 walls, spray foam insulation and triple-pane windows.

The customer asked if anything could be done to allow the floors to be warm and not overheat the home; the only thing I could think of was to increase the heat loss of the structure via a double-hung heat dump. While the couple appreciated the humor, they didn’t like the idea of opening a window. 

All this is to say that the issue could’ve been avoided right from the start. Heck, maybe in-floor heating wasn’t for them? The quiet, energy-efficient comfort of in-floor heating is something many dream of, but maybe this one point would’ve swayed their decision in the original planning.

Ultimately, you and your customers want the same thing: a functional, efficient heating system. I hope these tips help you achieve that. Add them to your checklist of best practices and keep up the good work. You don’t always have to learn the hard way, although those lessons are usually the ones you never forget!