How to Install a Taco Circulator Pump in a Basement

Clear away any movable items that block your access to the boiler. Verify that your new Taco circulator pump matches the configuration, size, flange style and capacity of the pump you're replacing. Disconnect electric power to the boiler by turning off the circuit breaker for the boiler’s power circuit. Close all supply and return valves for your hot water circulating lines. Manually close the electric zone valves. Close the boiler’s water supply valve. Wait 15 minutes to allow the pump line to cool.

Undo the screws holding the cover over the old pump’s power connection box. Remove the cover. Disconnect the electric wires. Pull the electric line out of the old pump’s wiring box. Place the bucket under the old pump to catch any dripping water. Unbolt the old pump using a socket wrench on the bolt head and an open-end wrench on the nut. The pump will be held in place by four flange bolts. Remove the four bolts and discard them. Pull the old pump out. Remove the old flange sealing gaskets from the flanges on either side of the pump and discard them.

Install the new flange gaskets supplied with the Taco pump into the gasket grooves in the pump’s mounting flanges. Install the new pump in the space formerly occupied by the old pump. Orient the new Taco pump in the same direction as the old unit. Fit the boiler flanges to the pump flanges and line up the flange bolt holes. Install new flange bolts and tighten them with the wrenches.

Wire the pump to the electric supply line. Thread the electric line for the pump into the Taco pump’s wiring box and secure it. Twist together the bare ends of the white pump wire and the white power supply wire. Twist together the bare ends of the yellow pump wire and the black power supply wire. Attach the ground wire to the pump’s grounding screw. Secure the electrical connections with wire nuts. Reattach the wiring box cover.

Turn on the boiler's water supply valve to refill the pump's water line. Open the valves to and from the hot water circulating lines. Turn on the electric power and start the boiler. If you're installing in the summer, run the pump for five minutes to purge trapped air from the impeller.