Giving the HVAC Boiler a Stay of Execution
Extending the life of that old cast-iron boiler
It’s a call from a customer that we’ve all received: “My boiler’s old, cranky, and leaking. I think we need to replace it with a new one.”
From a customer’s perspective, it makes sense. Many of the products central to everyday aspects of American life — from homes to cars to electronic gadgets — are no longer made to last.
If that’s been their experience as homeowners, why would a 30-year-old boiler be any different?
Hydronic pros have typically addressed this problem in two ways: by fixing the specific section with the leak — or perhaps the old elastomers between them — or replacing the entire boiler.
I’d like to suggest a third option: installing completely new piping while keeping the old boiler in place. Another option may include new controls with an outdoor reset, especially if it’s not already in place. But, for this column, I’ll focus on the hardware.
Over the years, I’ve evolved this approach by following what has become my personal rule of thumb: I treat heating systems not as a collection of individual parts but as total heating systems.
Regardless of the type of call I get, I take a look at not just the location of the leak but all of the pipes surrounding it. In a boiler heating system, all of the components have to work together for the water to get somewhere — for the Btu to do what we want them to.
Quite simply, Band-Aid fixes don’t work in the long run.
Take this scenario: You’ve been called to look at a leak in a home with a 25-year-old heating system, and you’ve determined it’s a problem with a fitting. You could simply replace the fitting in question at a relatively low cost to the customer.
But, if there’s a 25-year-old, leaky fitting in the house, the likelihood of a leak in another fitting 6 inches away is fairly high.
Why not complete all of the repairs at once and give your customers a whole new piping system that will add another 10-15 years of life to the boiler?
I recently completed one such job for homeowners in a high-end neighborhood who were planning to replace their heating system. The old cast-iron radiators were removed and updated with baseboards, and I created a completely new piping system, as well.
Yet, surrounded by entirely new components for the heating system, the original cast-iron boiler — the central component they initially planned to replace — was able to stay.
For this project, I started by removing all of the old steel and cast-iron supply and return piping, which I replaced with copper piping and Viega ProPress fittings. Once that was complete, I installed many new components: four Taco 007E circulator pumps, a Taco four-zone relay, a Taco 4900 air separator, a Taco boiler fill valve, and a number 30 expansion tank.
It’s important to remember that just because a heating system is old, that doesn’t mean it can’t handle new technology. A total or near-complete replacement of piping is an ideal time to introduce more efficient and technologically improved components to the system.
For example, high-efficiency circulators can provide customers with increased electricity savings over the next 10-15 years, which is another selling point. However, the value of their ability to greatly improve and control circulation is far more important. Zone valves are another ideal option for integrating better technology into the system.
If you recommend this approach, you could find that a customer objects with the concern that, despite the fixes, the boiler will fail anyway at some point soon down the road. While I’ve yet to run into this scenario myself, it’s an important possibility to keep in mind.
But there’s reassuring news: Even if the boiler needs to be replaced, all of that new piping can stay. In such a scenario, maintaining the old boiler for as long as possible also allows the customer to avoid the considerable upfront cost of replacing the entire system, which makes the payments more manageable for them.
More importantly, by taking this approach, you save the customer the time, stress, and cost of fixing a new leak every year — or worse, even sooner.
This also leads to the most significant benefit of all for any professional working in the hydronic heating field. By completing the job in one fell swoop, you improve your trustworthiness and reputation as an expert who gets things done the right way the first time.
Ultimately, that’s more valuable than the profit of even the most expensive boiler job.
Publication date: 7/17/2017