August 31, 2016 by Steve Goldie
When I sat down to write this article, my intention was to take a look at some of the most common issues in residential hydronic installations and examine the remedies. In the interest of not being repetitive I did a quick review of my most recent articles and I realized that I can be pretty negative.
Considering how much of my week gets filled up with troubleshooting, I could easily justify this as being somewhat of an occupational hazard. However, rather than pressing on with my “what not to do” crusade, I have chosen to embrace a more positive approach, highlighting some of the encouraging and more positive trends in our industry. Call it positive reinforcement or catching more bees with honey, whatever the case it is the new improved “glass half full” Steve Goldie.
The first positive trend is the proliferation of condensing boiler technology. Condensing boilers are by no means new. They first began appearing in the residential market about 15 years ago. In those early days there were few options and there was little understanding of how to properly install and apply this new technology. There were plenty of naysayers claiming potential fuel efficiency savings, if any, could never justify the extra costs of the boiler and its more complex installation.
Those days also were marked by far too many poor and improper installations. As with all new technology, there was a learning curve, a rather steep one in this case. Condensing boilers were a tough sell and the durable, tried and true cast iron atmospheric still dominated the market.
Today the landscape is far different; the number of condensing boilers available is staggering. I can offer you a good, better and best condensing option in just about any size range. Would you like floormount or wallmount? No problem we have both. Low mass, medium mass and even high mass designs are all available.
This proliferation of condensing boiler options has occurred for a number of reasons, including regulatory changes that mandate higher efficiency standards. Most of all these boilers exist because they work and the market demands them. Are there still naysayers out there promoting the virtues of old atmospheric technology? Of course there are, I can probably still find you people who believe the world is flat as well and just because they say it, it does not make it so. The encouraging thing is the majority of contractors now understand and see the value of a properly installed and operated condensing boiler.
The second encouraging trend, which is related to the first, is better boiler piping practice. In the early days of condensing boilers we saw a large percentage of very poor installations, which often resulted in breakdowns and failures. Why did installers who had been successfully installing atmospheric boilers for years all of a sudden forget how to properly pipe a boiler?
This is where I may get push back; they never knew how to properly pipe a boiler in the first place. Think about this for a minute, most of the new residential boilers were probably installed anywhere from the early part of the past century up to the mid 50s to early 60s. By then force air furnaces were taking over.
The vast majority of residential boilers installed by the mid 70s through the 80s would be retrofits installed for the most part by gas fitters and plumbers who were not around when the originals got installed. These installs, and I did plenty of them, would entail removing the old boiler, often a gravity system with no pump and oversized piping, and connecting the new boiler return and supply to the corresponding headers of the old system. There was not a lot of thinking to be done and very few residential systems had any zoning. They were simply one pump systems with a supply and a return. The difference between a good install and a bad install would simply come down to neatness of the piping. I have seen more than a few that were actually piped backwards and they still worked for years.
This is not meant as a criticism, I am plainly stating how things were. Most installers, my early self-included, simply did not have a thorough understanding of good piping practice because we did not need one to get the job done. The old saying, “necessity is the mother of all invention,” surely applies here.
By the late 80s and early 90s the advent of PEX pipe and the growing popularity of in-floor heating created renewed demand for hydronic heating, not simply in retrofits but in new housing. This new demand also created a need for a better trained, more knowledgeable hydronic installer. At times our industry has struggled to meet this need and most of us have more than enough examples of piping nightmare jobs we have encountered, however, I truly believe that there are more and more quality installers being developed all the time. Training is offered in many different ways by many entities such as wholesalers, manufacturers, trade organizations, community colleges, The Canadian Hydronics Council and so on. I do not want to get into the debate of whether or not hydronics installer should be a recognized trade or not, I will just say that there are many resources available to anyone willing to learn. In my opinion many are indeed learning and the level of competence seems to be on the rise, so glass half full Goldie is feeling encouraged.
The third encouraging trend I will mention is the growing popularity and availability of energy efficient variable speed pumps. Variable frequency drive (VFD) pumps are to pumping what modulating burners are to boilers. Rather than have a fixed speed pump chosen to meet an estimated or theoretical load, VFD pumps have sensors giving actual feedback of either pressure drop or temperature difference in a system. This information allows these smart pumps to calculate the actual load, and ramp up or slow down their speed accordingly to deliver the gallons per minute required, reacting and adjusting accordingly if and when this requirement changes. VFD pumps have been available for quite a few years now, but the past couple have seen a significant surge in popularity, partly due to lower costs and partly due to a better understanding of the real benefits they offer.
When I started in wholesale many would have said I was crazy if I predicted that one day every boiler we sold would be a modulating condensing model, and yet, that is pretty much the reality. We are not far away from the day when virtually every pump sold by wholesalers will have some form of VFD technology built in.
I am confident that more and more of the people installing these technologies will be knowledgeable and competently up to the task. This might all mean that my troubleshooting career will be over but no worries, glass half full Goldie will just look for a job as a positive-thinking motivational speaker.
Steve Goldie learned his trade from his father while working as plumber in the family business. After 21 years in the field, he joined the wholesale side of the business in 2002. He is frequently called on to troubleshoot systems and to share his expertise with contractors. He can be reached at firstname.lastname@example.org.