Q: Your technician replaced one of our pumps on our boiler system. We have several others left that may fail, should we be replacing them all?
A: To start with, and to clarify some boiler vernacular, we replaced a “circulator”, not to be confused with a “pump”, more on that below during the amazing conclusion of the article. This circulator replaced may have been one of many, but often its service life depends on the purpose and how it was piped. Most residential boiler systems will have at least one circulator and depending on the size of the system, perhaps an entire wall of them (hint: more is not always better, BUT size always matters). One properly sized circulator can provide adequate flow to an average sized home with baseboard heaters or big ol’ fat radiators. This is due to their relatively low restriction in the elements and distribution. Adding all the modern accoutrements to a system such as multiple zones, radiant, indirect fired water heating, snow melt, etc, is where flow challenges are created.
There are any number of heating and cooling systems AirWorks is required to design, repair, and maintain. With “hydronics” (more boiler vernacular), this is the application of heat transfer using water as the medium. Just like an artist’s medium may be oils, watercolors, or tin foil (?), ours, in this case is water. Creating (or often redesigning) a system that will providing consistent water flow and thus heat transfer, and thus warm feet is what it’s all about. Often boiler rooms, big and small (usually too small) can be an overwhelming mazes of pipes, plumbing, and control wiring. Compared to a furnace where it’s normally return air ducting into a rectangular box, and hot air out the top, wa-la! Boiler rooms rarely release their secrets quite that easy. The comings and goings of all those pipes have consistent properties of BTU content and flow rates. Our job is to decipher that with a few well placed temperature reading instruments and voltage meters. If we are lucky, the solution is a worn out circulator (if we could ever be so lucky).
Back to the question at hand. The circulator that was replaced was installed in the “primary loop”, which is the main driver of water moving through the boiler. This component will be running anytime the boiler system is heating, no matter what task is occurring. The odds of a shorter service life are ensured however ten years or better should be expected. Any number of situations could negatively affect how long one may last. Water quality is a biggie and this usually goes south from improperly mixing cast iron (ferrous metals) with copper and brass (non-ferrous) metals. This di-electric corrosion of the cast iron will slowly create leaks and leave particulate floating around just waiting to scour bearings and clog stuff up. Air in the hydronic system as well as low system pressure can cause pumps to cavitate and suffer a quick (and usually) noisy ending. AirWorks maintains boilers to prevent just this sort of thing. If you have a have a boiler system, you may have found they are easy to ignore with no filters to change but left unattended, especially for years, be afraid, be very afraid.
As the drums roll, the crowd leans forward awkwardly awaiting the differences in the definition between a pump and a circulator. As it was explained to me, a circulator is like motor driving a Ferris wheel. Since a boiler system is a “closed system” it just moves water up to the heat emitters and then back down to the boiler, and again, and again. A pump is designed to overcome atmospheric pressure and move water, say from a well to your water heater, to you shower head, and AAAAA, pure bliss. So now you know, and let us know if AirWorks can help maintain your boiler system. We are scheduling now for the spring season, call (406) 630-4170
