Taco CI Series pumps are close-coupled end-suction centrifugal pumps designed for commercial hydronic and water applications, including heating, air conditioning, pressure boosting, cooling-water transfer, water supply, solar, geothermal, and water/glycol systems. But identifying the CI Series as the correct pump type is only the beginning of the selection process.
The CI Series covers a wide range of hydraulic sizes, motor configurations, materials, speeds, and operating points. Selecting a CI pump therefore requires matching the specific pump curve and configuration to the system - not simply choosing a model based on pipe size, horsepower, or the broad performance range of the CI family.
Video credit: Taco
Taco CI Series Introduction
The Taco CI Series is a family of close-coupled end-suction pumps. An end-suction centrifugal pump draws fluid into the suction connection at the end of the pump casing and discharges it through a separate discharge connection.
In a close-coupled arrangement, the pump and motor form a compact assembly without the separate pump bearing frame and flexible coupling associated with a conventional base-mounted end-suction pump.
That distinction is important when evaluating the mechanical room footprint, installation arrangement, motor configuration, and future service requirements.
Taco currently lists CI Series applications including:
- pressure boosting
- hot-water heating
- closed cooling circuits
- air-conditioning systems
- hydronic heating and cooling
- water/glycol concentrations up to 50%
- solar systems
- geothermal systems
What Makes the CI Series Pumps Different?
Dry-shaft Design
The Taco CI Series uses a dry shaft design, meaning the pump shaft is isolated from the circulating system fluid. The practical advantage of this feature is corrosion protection for the shaft.
Because the shaft is isolated from the circulating fluid, corrosion-resistant shaft materials are generally not required solely to protect the shaft from system fluid.
This does not, however, mean fluid chemistry can be ignored when selecting the pump. The casing, impeller, shaft sleeve, mechanical seal, and other wetted components still need to be matched to the actual fluid and operating conditions.
Replaceable Slip-On Shaft Sleeve
The CI Series uses an easy-to-replace slip-on shaft sleeve.
This matters because mechanical-seal maintenance should not automatically require sacrificing or replacing the motor shaft itself. The goal is to simplify seal service in the field and reduce maintenance costs.
Rear Pullout Construction
For mechanical rooms where suction and discharge piping are already installed, a rear pullout design can reduce the amount of piping work involved when servicing internal pump components.
The design advantage still depends on providing the physical service clearance required for the actual installation. Pump placement should therefore account for future maintenance access - not only the footprint required to install the unit initially.
Top Centerline Discharge
This arrangement helps simplify piping layouts, reduce piping strain, and enable the pump to self-vent.
Seal-Line and Pressure Tappings
Flush seal-line taps are provided so filtration can be added to help protect the mechanical seal from particles that may be present in open systems. Pressure tappings are also provided at the suction and discharge connections.
Taco CI Series Performance Range
Below is the product-family summary, which gives the following general Taco CI Series performance data:
| Parameter |
Taco CI Series Family Data |
| Maximum Fluid Temperature | 250°F / 120°C |
| Maximum Working Pressure (standard) | 175 PSIG |
| Maximum Working Pressure (optional) | 300 PSIG |
| Water Flow Range | 20 - 2,650 GPM |
| Head Range | 5 - 380 ft |
| Motor Power Range | 1/2 - 60 HP |
| Pump Size Range | 1.5 - 6 in. |
This table is useful for understanding the approximate scope of the Taco CI series, but it should not be used as the final pump-selection criteria.
Why the Family Range Should Not Be Used to Select a Pump
There is an important distinction buried in Taco's current data. The CI series table summary lists a flow range of 20-2,650 GPM and a head range of 5-380 feet. However, Taco's model-level listings in their technical documentation include operating-range values below 20 GPM and models with listed head ranges approaching 390 feet. Pump curves can be checked here: Taco CI Series Product Page.
For example, Taco documentation lists one of the available CI1207D models with a water flow range beginning around 8 GPM and another CI1209C model available with head values reaching approximately 390 feet.
It means the family-level range should be treated as an overview rather than a selection table. The correct CI pump must be selected from the performance curve and submittal data for the specific hydraulic size, speed, impeller, motor, and configuration under consideration.
That distinction can prevent a selection mistake: deciding that a pump is suitable simply because the required system flow and head fall somewhere inside the advertised range of the entire product family.
What You Need to Know Before Selecting a CI Series Pump
A useful CI selection starts with the system operating requirement; the design flow and total dynamic head establish the required operating point.
From there, the applicable Taco performance curve can be evaluated to determine which hydraulic size and impeller configuration can operate at that point.
Selection should then verify the remaining Taco CI Series pump configuration available:
| Selection Item |
What Needs to Be Verified |
| Hydraulic Requirement | Design GPM and total dynamic head |
| Operating Point | Position on the specific Taco pump curve |
| Fluid | Water or glycol concentration |
| Temperature | Operating fluid temperature |
| Pressure | Required system working pressure |
| Pump Construction | Casing, impeller, sleeve, wear components, and seal materials |
| Motor | Horsepower, RPM, efficiency, enclosure, voltage, phase, and frequency |
| Connections | Suction size, discharge size, and flange requirements |
| Controls | On/off, VFD, or other project-specific control requirements |
| Service Requirement | Access and clearance for future maintenance |
This is particularly important with the CI family because a hydraulic model designation does not necessarily identify every feature of the complete assembled pump.
Why the Full CI Pump Configuration Matters
Taco CI Series pumps have many possible configurations.
Consider a model such as CI6009.
This current CI6009 model has several configurations from different motor manufacturers, with varying horsepower ratings, motor enclosures, impeller materials, seal arrangements, and other construction options.
Similarly, CI6011 model listings include multiple motor and speed configurations under the same basic hydraulic model family.
“I need a CI6009” is not necessarily sufficient information to identify the pump to be ordered.
The complete configuration, including the Taco part number or the existing pump nameplate, must be verified to identify the correct pump.
Matching only the series and hydraulic-size designation can overlook differences in motor voltage, phase, speed, horsepower, enclosure, impeller material, mechanical seal, flange arrangement, or another project-specific option.
CI vs. FI vs. SCI vs. SFI: Which Taco End Suction Family Fits the Application?
The CI Series is not Taco's only end suction pump family.
Understanding the basic architecture of the alternatives helps determine whether the CI Series is the correct starting point.
| Taco Series | Basic Configuration | Main Distinction |
| CI | Close-Coupled End Suction | Compact conventional close-coupled pump arrangement |
| SCI | Close-Coupled End Suction with integrated VSD | Adds integrated variable-speed control and operating modes |
| FI | Base-Mounted End Suction | Separate bearing-frame/base arrangement and larger upper-end capacities |
| SFI | Base-Mounted End Suction with integrated VSD | Combines a frame-mounted arrangement with integrated variable-speed control |
The Taco SCI Series is also close-coupled (as with the CI Series) but with an integrated VSD system that responds to changes in system demand.
The Taco FI Series is base-mounted rather than close-coupled. The FI design uses a bearing frame and structural steel base, and its range extends through larger pump sizes and horsepower than the CI family.
The Taco SFI Series applies that integrated variable-speed approach to Taco's base-mounted end-suction platform, making it an option to consider when the application calls for a frame-mounted pump arrangement with integrated control.
Those differences matter.
A CI, FI, SCI, and SFI may address similar hydronic applications, but they should not be treated as automatically interchangeable pump packages. Hydraulic performance, physical dimensions, controls, motor characteristics, materials, and replacement requirements must still be evaluated for the specific unit.
When Does a Taco CI Series Pump Make Sense?
The CI Series is a logical family to evaluate when the application requires a commercial end-suction pump and a close-coupled configuration fits the project's hydraulic, dimensional, motor, and service requirements.
Its rear pullout arrangement, replaceable shaft sleeve, dry shaft construction, top centerline discharge, pressure tappings, and seal-line provisions are particularly relevant when serviceability is an important part of the pump specification.
But the most important selection question is not simply: “Can a CI Series pump produce this much flow?“
It is: “Which exact CI configuration can operate at the required design point while meeting the fluid, pressure, temperature, material, motor, electrical, control, piping, and service requirements of this system?”
That is the level at which the final pump selection should be made.
Selecting a CI Series Pump
The Taco CI Series can be selected for a wide range of hydraulic and motor configurations. Before ordering, have the system design flow and head available along with fluid type and concentration, operating temperature, system pressure, electrical requirements, and any material or motor specifications required by the project.
For pump replacement, it's crucial to provide the complete pump nameplate and, when available, the Taco part number; these details allow evaluation of the actual pump configuration rather than relying on a family name or nominal pump size alone.
Browse Taco CI Series pumps from Liberty Supply or contact the Liberty Supply team for help identifying the configuration that matches your application.
Frequently Asked Questions
Check the pump and motor nameplates for the Taco model or part number, horsepower, voltage, phase, RPM, and any available impeller or configuration information. Use those details to verify the exact unit against Taco's current submittal and performance data.
Not automatically. The motor horsepower must match the selected pump configuration, operating point, impeller, speed, and motor loading. Verify the specific Taco performance curve before changing horsepower.
Provide the existing model or part number, required flow and head, fluid type, temperature, system pressure, motor horsepower, RPM, voltage, phase, and any known impeller or material requirements. A clear photo of the pump and motor nameplates is also useful.
No. Connection size alone does not determine pump performance. Select the pump from the required flow and total dynamic head, then verify the specific CI performance curve and configuration.
Impeller diameter affects the flow, head, and power characteristics of the pump. Different impeller diameters within the same pump size can produce different performance, so the correct diameter should be verified from the applicable Taco performance curve.
