Introduction to Circulators

Last week we talked about the humble heat exchanger and its role in safely keeping you toasty through frigid winters. In water-based heating systems, the next major component for us to look at is a circulator pump. These come in all shapes and sizes, from a tiny piece of equipment on a residential furnace to a back breaking hundred-plus pound chunk of machinery in an office building. In order to understand the circulator, we also need to understand the structure and reasoning behind a hot water heating system.


First, let’s answer the big question: Why Water?

Water is an incredibly dense liquid. It can absorb an enormous amount of heat and then readily transfer it into anything it touches. This is the reason we sweat: water moves the heat from us into the air more efficiently than just straight air contact. It’s the same reason cars have water cooling that is fed to a radiator. The water more readily absorbs and gives off the heat. Other materials either can’t match that performance or if they do, they’re toxic.


These properties provide for an incredibly efficient heating system. A furnace can fire, create a larger than necessary water supply, store it in an insulated tank, and spend the rest of the day shut down. This cuts down on the amount of fuel needed and can extend the hardware’s effective lifetime by needing it less of the time. Other systems need to fire more frequently to maintain an acceptable environmental temperature.


Circulator In Action

This is where the circulator pump comes in. With this sort of system, the furnace is self-regulating. It monitors the water supply and temperature, once the supply diminishes or the temperature falls below a certain level, it re-fires to replenish the supply. This also allows the same furnace to provide hot water for sinks, bathrooms, laundry machines, and the coffee machine outside your boss’s office. When the thermostat detects a sufficient drop in temperature, it turns on the pump, hot water fills the pipes, and things warm up pretty quickly. Cool water is pushed out of the system and back to the furnace for reheating when it next fires. During the Spring and Summer, the same pump sits dormant, allowing hot water to flow to any pipes that aren’t there for heating.


Depending on your situation, it may even be pretty easy to handle a circulator pump failure. Many pumps are modular, such that a failed motor can be replaced with little disturbance to the piping. This helps bring down maintenance costs, instead of calling and ordering a new, $5000 pump, you order the much cheaper motor, bearing, flange, or anything but the whole machine. Particularly unlucky individuals may have a failed impeller or issues with the pump body, which will involve more work to replace. Residential plumbers and DIY’ing home owners may also find themselves getting a cold shower during repairs, if there’s no good way to drain the system ahead of time.


And now a word from our sponsor!

Does your pump sound like a transmission from Crazy Bob’s Daily Deals and Discount Transmissions, from the scary part of town? Did you find a nice, cold puddle keeping your circulator and furnace nice and toasty through these long winter days? Your heating system’s got problems and we have solutions.


You don’t need to read that crusty, rusty part number off that antique pump older than the space program either. Just tell us the make and model or serial number of your furnace and we’ll track down a compatible, new pump. We have experts who rattle off part numbers like a play by play of the super bowl.


We carry pumps and replacement parts from Bell & Gossett, Taco, Grundfos, and Armstrong. We can take your order for a new impeller today and have it to at your doorstep tomorrow. We’ll keep you out of the cold.


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