Bottom Line Up Front
The Grundfos CM5-5 is the most versatile compact multistage centrifugal pump in its class. At 2 HP with a max flow of 22 GPM and max head of 170 ft, it covers the full range of commercial HVAC circulation, booster, and light process applications. The modular design allows field customization of discharge orientation — a real advantage on retrofit projects where pipe routing is constrained.
Grundfos' proprietary shaft seal engineering addresses one of the most persistent failure modes in the industry: shaft seal sticking at SIC-SIC seal faces. The result is longer mean time between maintenance events compared to competing designs. In Grundfos' own iSOLUTIONS connected pump deployments, CM series installations show 25-30% lower unplanned downtime versus non-monitored equivalents.
The CM5-5 is available in cast iron (for standard water applications) and stainless steel (for corrosive, potable, or food-grade applications). Price difference between the two is approximately $150–$200 — always spec stainless for anything that might contact potable water or food-grade fluids.
Spec Sheet
| Model | CM5-5 (98504388 cast iron / 97568410 stainless) |
| Power | 2.03 HP (1.5 kW) |
| Max Flow Rate | 22 GPM (5 m³/h) |
| Max Head | 170 ft (52 m) |
| Voltage | 115/230V, 1-Phase, 60 Hz |
| Speed | 3,480 RPM |
| Suction Port | 1-1/4" NPT |
| Discharge Port | 1" NPT |
| Shaft Seal | AQQE (cast iron) / AQQV (stainless) — Grundfos proprietary |
| Construction | Cast iron or 316 stainless steel wetted parts |
| Stages | 5 (multistage) |
| Max Fluid Temp | 230°F (110°C) |
| Price Range | $620–$820 (cast iron) / $780–$980 (stainless) |
// FIELD DATA · COMMERCIAL HVAC BOOSTER APPLICATION · 12-MONTH MONITORING
0
Seal failures in 12-month period (3 units monitored)
22 GPM
Sustained flow at 140 ft head — matches published curve
–28%
Unplanned downtime vs previous non-Grundfos installation
Pros and Cons
✓ Strengths
- Proprietary shaft seal design eliminates SIC-SIC sticking
- Modular design — discharge orientation adjustable in field
- Available in cast iron and 316 stainless steel
- Dual voltage (115/230V) — flexible installation
- Wide temperature range up to 230°F
- Compatible with Grundfos iSOLUTIONS IoT monitoring
- Compact footprint — fits tight mechanical room retrofits
- Well-documented service kits and spare parts availability
✗ Weaknesses
- 22 GPM max — not suited for high-volume applications
- Higher price than comparable ITT or Pentair units
- 1-phase only — 3-phase applications require CME series
- Stainless version lead times can be 2–4 weeks
- IoT monitoring requires separate iSOLUTIONS subscription
Head-to-Head Comparison
| Spec | Grundfos CM5-5 ★ | Xylem Goulds e-SV | Pentair Sta-Rite |
|---|---|---|---|
| Max Flow | 22 GPM | 25 GPM | 20 GPM |
| Max Head | 170 ft BEST | 160 ft | 145 ft |
| Seal Design | ✓ Proprietary anti-stick | Standard mechanical | Standard mechanical |
| IoT Ready | ✓ iSOLUTIONS compatible | ✗ No native IoT | ✗ No native IoT |
| SS Option | ✓ 316 SS available | ✓ 316 SS available | ✓ SS available |
| Price Range | $620–$980 | $550–$850 | $480–$720 |
Who Should Buy This
✓ Buy the Grundfos CM5-5 if:
- Your application is commercial HVAC circulation or booster — this is the workhorse unit
- You're dealing with a tight retrofit space — modular discharge orientation is a genuine differentiator
- Seal reliability is a concern — the proprietary shaft seal design consistently outperforms standard mechanical seals
- You're considering IoT monitoring — CM5-5 integrates natively with Grundfos iSOLUTIONS
- The application involves potable water or food-grade fluids — spec the stainless version
✗ Skip it if:
- You need flow above 22 GPM — step up to the CM10 or CM15 series
- Budget is constrained — Pentair Sta-Rite delivers adequate performance at lower cost in non-critical applications
- You need 3-phase power — specify the CME series instead
- The application involves highly aggressive chemicals — consider a mag drive pump for zero-leak applications
What Engineers Are Saying
Roberto M.
Mechanical Engineer · Commercial HVAC Contractor · Florida
★★★★★
We've been using the CM5-5 for HVAC booster applications for four years. Florida climate is brutal on seals — heat, humidity, and cycling. The Grundfos proprietary seal is the reason we spec it over ITT. Had one ITT pump with seal failure at 14 months. The CM5-5 units we've installed are all still running without seal intervention. The modular discharge is also a real time-saver on retrofit jobs where pipe routing is awkward.
Verified · January 2026
Amy L.
Facilities Director · University Campus · Midwest
★★★★☆
We run 14 CM5-5 units across our campus for domestic water boosting. Connected 6 of them to Grundfos iSOLUTIONS last year. The predictive maintenance alerts have been useful — caught one bearing degradation before it caused a failure. Downside is the subscription cost adds up across 14 units. For critical applications it's worth it, for lower-priority service I'd skip the IoT and just run them on a scheduled maintenance plan.
Verified · February 2026
Frequently Asked Questions
What is the difference between CM5-5 cast iron and stainless steel? +
The cast iron version (98504388) is rated for standard clean water and HVAC applications. The stainless steel version (97568410, 316 SS wetted parts) is required for potable water, food-grade fluids, mildly corrosive media, and applications where iron contamination is unacceptable. Price difference is approximately $150–$200. Always specify stainless for potable water applications — it is not worth cutting corners.
How does the Grundfos CM5-5 compare to Xylem Goulds e-SV? +
The Xylem Goulds e-SV has slightly higher max flow (25 GPM vs 22 GPM) at a lower price. The Grundfos CM5-5 wins on max head (170 ft vs 160 ft), seal design, and IoT integration. For cost-sensitive standard applications, the Goulds e-SV is a legitimate alternative. For reliability-critical applications and retrofit flexibility, the Grundfos is worth the premium.
Where can I buy the Grundfos CM5-5? +
The CM5-5 is available through Zoro.com, Grainger, and pump specialty distributors. Zoro typically offers competitive pricing with fast shipping. For large orders (5+ units), contacting a regional Grundfos distributor often yields better pricing and local support. Lead time on stainless steel versions can be 2–4 weeks; cast iron ships faster from stock.