Are you tired of waiting for hot water to reach your shower or kitchen sink—even after upgrading to a tankless water heater? You’re not alone. While tankless heaters deliver endless hot water, they don’t always deliver instant hot water at the tap. The good news? With a few smart tweaks and the right accessories, you can dramatically reduce the wait time and enjoy near-instant hot water whenever you need it. This guide covers the reasons for delays, top fixes, best products, and key tips to get hot water faster from any tankless system.
Quick Picks: Best Products for Faster Hot Water with Tankless Heaters
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Best Recirculating Pump Kit:
Grundfos Comfort System Recirculator Pump Kit – Plug-and-play, easy install, fits most homes. -
Best Pump for Retrofit Installs:
Watts Premier Instant Hot Water Recirculating System – Simple under-sink install, no return line needed. -
Best Smart Pump:
TacoGenie Hot Water Demand Pump – Push-button operation, only runs when you need it.
Why Does It Take So Long for Hot Water from My Tankless Heater?
- Distance from Heater: The further your faucet is from the tankless unit, the longer hot water takes to travel through the pipes.
- Cold Water Left in Pipes: When you turn off the hot tap, water in the pipes cools down. Next time you turn it on, all that cool water must be flushed out.
- Flow Rate Minimums: Most tankless heaters need a minimum flow (usually 0.4–0.7 GPM) to “fire up.” Low-flow fixtures may not trigger the heater right away.
- Recirculation Absence: No built-in recirculating loop means hot water isn’t kept circulating through your pipes—resulting in a delay.
- Pipe Size & Material: Larger or metal pipes hold more water and cool off faster, increasing wait times.
Solutions: How to Get Hot Water Faster from a Tankless Water Heater
- Install a Recirculating Pump: The #1 fix. These pumps keep hot water circulating through your plumbing so you get near-instant hot water at every tap—no more waiting.
- Use a Demand-Controlled Pump: Smart “on demand” pumps activate only when you need hot water, saving energy and reducing wear.
- Add a Return Line (for New Homes): Dedicated hot water return lines deliver the fastest, most efficient instant hot water.
- Upgrade to Low-Volume Pipes: Using PEX or smaller diameter lines in remodels can reduce the “dead leg” and wait time.
- Insulate Your Hot Water Pipes: Pipe insulation keeps water hotter for longer between uses, minimizing cold water flushes.
- Adjust Your Heater’s Flow Sensors: If possible, lower the minimum flow rate setting (see your manual or ask your plumber).
- Install Point-of-Use Tankless Units: For remote bathrooms or kitchens, consider a small 110V unit under the sink for immediate hot water.
Buyer’s Guide: Choosing a Recirculating Pump for Tankless Water Heaters
- Compatibility: Choose a pump designed for tankless systems (some standard pumps don’t work due to flow sensor issues).
- Install Location: Most are installed at the water heater or under the farthest sink. Choose based on your plumbing layout.
- Return Line Required? Some systems use your cold water line as a return, avoiding new pipe installation—ideal for retrofit.
- Activation Method: Timer, thermostat, or push-button. “On demand” pumps are most efficient for tankless heaters.
- Noise Level: Quality pumps run almost silently. Check reviews for noise ratings.
- Warranty: Look for at least a 2-year warranty and accessible customer support.
Top Recirculating Pumps for Tankless Water Heaters: Reviews
Grundfos Comfort System Recirculator Pump Kit
- Includes pump, valve, and all parts for most homes
- Easy installation, fits at heater or under sink
- Works with many tankless and tank systems
- Quiet, reliable, and energy-efficient
Final Verdict: The best all-around recirculating pump for quick hot water and simple installation.
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Watts Premier Instant Hot Water Recirculating System
- Installs under farthest sink—no return line needed
- Timer for scheduling hot water delivery
- Reduces water waste and waiting time
- Works with most tankless units (check minimum flow requirements)
Final Verdict: The best kit for older homes—get fast hot water without repiping.
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TacoGenie Hot Water Demand Pump
- Push-button activation—hot water on demand
- Energy-saving, runs only when needed
- Quiet, efficient, and long-lasting
- Simple install under any sink or bathroom vanity
Final Verdict: Best for energy-conscious families who want fast hot water only when they ask.
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Comparison Table: Best Recirculating Pumps for Tankless Water Heaters
| Product | Install Location | Return Line Needed? | Activation | Best For | Price Link |
|---|---|---|---|---|---|
| Grundfos Comfort Kit | Heater or sink | No | Timer/Thermostat | Most homes | View |
| Watts Premier System | Under sink | No | Timer | Retrofit, older homes | View |
| TacoGenie Demand Pump | Under sink | No | Push-button | On-demand, energy savings | View |
FAQ: Getting Faster Hot Water from Tankless Heaters
- Why does it take so long to get hot water with tankless?
Cold water in the pipes must be pushed out before hot arrives. The longer the pipe run, the longer the wait. - Will a recirculating pump increase my energy bills?
Minimal increase—most pumps use little power and save water. Demand-controlled models minimize energy use even more. - Can I install a recirculation system myself?
Many homeowners can install basic kits. More complex installs or adding a return line may need a plumber. - Will this work with my brand of tankless heater?
Most modern pumps are compatible, but always check your model’s specs or call the manufacturer to confirm. - Does pipe insulation help?
Yes! Insulating hot water pipes keeps water hotter longer and shortens wait times, especially in cold basements or crawlspaces.
Conclusion
You don’t have to live with slow hot water, even if you’ve gone tankless. With a quality recirculating pump, smart upgrades, and a few easy tweaks, you can enjoy instant hot water at every tap and cut water waste too. Pick from the best solutions above and enjoy the comfort and convenience your tankless heater was meant to deliver!