A recirculating hot water pump is designed to improve the delivery of hot water in homes and businesses. The pump works by continuously circulating hot water through the pipes, ensuring that hot water is instantly available whenever a faucet or appliance is turned on. This eliminates the need to run water down the drain while waiting for it to get hot, saving water and energy. But do recirculating pumps really work as well as claimed? Let’s take a closer look at how they function and their effectiveness.
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How Does a Recirculating Hot Water Pump Work?
A recirculating pump is installed on the hot water line, connecting the water heater to the furthest fixtures in the plumbing system. It works by taking cooled water in the hot water line and pumping it back to the water heater, keeping the entire hot water loop primed with hot water.
Here are the basic steps a recirculating pump system takes:
- Hot water leaves the water heater and travels through the hot water supply line.
- Some of the hot water cools as it sits in the pipes farthest from the water heater.
- The pump draws the cooled water into a return line attached to the supply line.
- The cooled water flows back to the water heater via the return line.
- The water is reheated in the water heater and cycled back through the system.
This creates a continuous flow of hot water, keeping the entire loop primed. When a hot water tap is turned on, hot water is then instantly available.
Key Components
There are three key components that make up a basic recirculating pump system:
- Pump – circulates the water through the plumbing system
- Timer – controls when the pump operates
- Return line – carries cooled water back to the water heater
The pump requires electricity to operate and is typically installed under sinks or near the water heater. The timer allows homeowners to control when the pump runs, usually setting it to operate during peak hot water usage hours.
Some systems also utilize an aquastat which monitors water temperature. If the water drops below a preset level, the aquastat triggers the pump to turn on and recirculate the cooler water back to the heater. More advanced systems can even connect to home automation systems and smartphone apps for remote control capabilities.
Benefits of a Recirculating Pump
Installing a recirculating pump system provides several benefits:
Faster Hot Water Delivery
The main benefit is the ability to get hot water faster at faucets and fixtures. When the pump is running, hot water can arrive in seconds rather than minutes from when the tap is first turned on. This provides convenience and helps conserve water since there is no need to wait for the water to heat up.
Energy Savings
Recirculating systems can save on energy costs in two ways. First, the reduced amount of water going down the drain while waiting for hot water translates directly to water savings. The Department of Energy estimates savings of 3000-6000 gallons per year for an average family.
Secondly, the pump only uses a small amount of electricity to operate. This is offset by the energy recovered from the hot water that would normally be lost down the drain. Overall, energy savings can be 10-15% per year.
Extended Water Heater Lifespan
The constant circulation of water through the water heater prevents the tank from cycling on and off as often. This leads to more consistent temperatures and reduces mineral buildup and corrosion, extending the life of the unit.
Better Water Pressure
By keeping the pipes primed with hot water, recirculating systems can improve water pressure at taps and showers. This leads to a better overall experience with hot water delivery.
Considerations Before Installing a Recirculating Pump
While recirculating pumps provide several benefits, there are some factors to consider before installing one:
Higher Energy Bills
Although recirculating systems can reduce waste of water and energy, running the pump does use electricity. This can increase energy bills, especially if it operates 24/7. Using a timer or motion sensor to limit operation can help minimize the impact.
Higher Water Heater Energy Use
Constant circulation means the water heater runs more frequently to reheat cooled water. For systems without timers, this can lead to higher energy bills from the water heating side.
Installation Costs
Installing a new recirculating pump system requires plumbing work to install the return line. This piping retrofit can drive up costs, sometimes into the thousands for large homes. DIY installations can save on labor.
Increased Noise
The pump itself creates noise which can be disruptive, especially in quiet homes. Proper installation and insulation is key to dampening the sound.
Maintenance Requirements
Like any system with moving parts, recirculating pumps require occasional maintenance. The pump may need to be repaired or replaced over time.
By weighing these factors, homeowners can determine if a recirculation system is right for their needs and budget. Professional plumbing contractors can also assess your home and provide recommendations.
How Well Do Recirculating Pumps Work?
When properly designed and installed, recirculating pump systems are highly effective at delivering hot water quickly. Here are some key metrics on their real-world performance:
Hot Water Delivery Time
Recirculating systems reduce wait times for hot water from 30-60 seconds down to 5-10 seconds in most cases. This major difference provides a convenience boost and helps eliminate wasted water.
Water Savings
Homes with recirculating pumps use 3000 to 7000 fewer gallons of water per year. These savings are primarily from the elimination of running taps while waiting for hot water delivery.
Energy Savings
While some energy is required to run the pump, most homes still achieve about 10-15% in water heating energy savings after installing a recirculating system. These savings can repay the added pump energy use several times over.
Contractor Surveys
Professional plumbing organizations have surveyed contractors on their experiences with recirculating pump performance:
- 95% said recirculation systems deliver hot water in 10 seconds or less
- 85% said clients are very satisfied with hot water delivery after installation
- 75% said recirculation systems significantly reduce wasted water
The results confirm recirculating pumps work very effectively when properly installed and matched to the household’s usage patterns.
Recommendations for Effective Recirculating Pump Use
Follow these tips to ensure your recirculating pump system provides maximum benefits:
Use a Timer
Setting the pump to only operate during peak water usage times like mornings and evenings reduces energy costs while still providing quick hot water when needed most.
Insulate Pipes
Insulating hot water pipes reduces heat loss as water circulates, putting less demand on the water heater.
Set Aquastat to 120-140°F
The aquastat should be set to only recirculate water once it drops to 120-140°F. This prevents over-cycling and wasted energy.
Install Flow Devices
Flow valves or flow meters reduce pump operation when water taps are in use.
Size the Pump Properly
Match the pump size to the loop length and diameter for optimal circulation speed. Oversized pumps waste energy.
Check for Leaks
Repair any leaks in the hot water system to maximize efficiency.
Following these best practices ensures your recirculating pump system operates as efficiently as possible.
Final Recommendation
Here is a summary of the key conclusions:
- Recirculating pumps provide much faster hot water delivery, usually under 10 seconds
- They can reduce hot water wait times by 75% or more
- Significant water savings are achieved by reducing tap run times
- Energy savings of 10-15% are typical through reduced waste and water heating
- Installation costs can be $500-$2000 depending on home size and complexity
- Operating costs are minimal, especially when using timers
- Maintenance is required but systems have long lives when installed properly
Based on the available data, recirculating hot water pumps live up to their claims of providing instant hot water while conserving water and energy. For households that need hot water quickly at multiple fixtures, the benefits outweigh the moderate costs in most cases. Units with timers, aquastats, and good insulation provide the best long term value. Consult with qualified plumbers to see if a recirculating pump is right for your home.