Hot water circulation pumps are used to circulate hot water from a water heater to plumbing fixtures throughout a home or building. The purpose of a hot water circulation pump is to provide hot water quickly at taps and showers, without having to wait for cold water sitting in pipes to flow out before hot water can arrive from the water heater.
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Types of Hot Water Circulation Pumps
There are two main types of pumps used for hot water circulation:
- Standard circulation pumps
- Demand-based circulation pumps
Standard Circulation Pumps
Standard circulation pumps operate continuously to keep hot water flowing through the plumbing system. They are relatively inexpensive and simple to install. However, standard circulation pumps use energy constantly, even when hot water is not needed. This can lead to higher energy costs from pumping and keeping water hot.
Standard circulation pumps are a good choice for systems with consistent, frequent hot water usage. They ensure hot water is always available when a tap or shower is turned on. But in homes or buildings with varying hot water usage patterns, demand-based circulation pumps may be a better choice.
Demand-Based Circulation Pumps
Demand-based circulation pumps only operate when hot water is needed. They can sense when a faucet is turned on and immediately start circulating hot water from the water heater to the fixture. This provides hot water rapidly while conserving energy compared to continuously running pumps.
Demand-based circulation systems use a temperature sensor at the end of a hot water line to monitor water temperature. When the temperature drops below a set point, indicating hot water is being used, the pump activates to deliver more hot water. Demand pumps stop operating once the temperature rises again after hot water usage stops.
Demand-based circulation pumps are more complex and expensive to install than standard pumps. They require temperature sensors and controllers to activate the pump when needed. However, they can provide significant energy savings in the long run by only operating when necessary.
Choosing a Hot Water Circulation Pump
Several factors should be considered when selecting a hot water circulation pump for a residential or commercial building:
- Energy usage – Standard pumps use more energy than demand-based pumps. Consider energy costs and savings when selecting a pump type.
- Hot water usage patterns – Homes with consistent, frequent hot water needs may benefit from standard pumps. Intermittent usage favors demand-based pumps.
- Pump size – Pump size should be matched to the length and size of plumbing in the system.
- Installation cost – Demand-based pumps have a higher installation cost due to added controls and sensors.
- Noise level – Some pump types are quieter than others.
It is a good idea to consult with a qualified plumber during the circulation pump selection process. The plumber can assess the home or building’s hot water system and provide recommendations on the optimal pump type and size.
Hot Water Circulation Pump Styles
Hot water circulation pumps come in several main styles:
- Inline pumps – Inline pumps are installed directly in the hot water recirculation line. No separate pump housing is required. Inline pumps are compact but can be difficult to service or replace.
- Small circulators – Small circulator pumps are designed specifically for hot water recirculation. They are compact and easy to install in small spaces.
- Standard wet rotor circulators – These general utility pumps can adapt for hot water circulation. They require more space for installation but are often less expensive.
- Taco 00 pump – The Taco 00 is a specialty bronze pump for hot water circulation. It is durable and reliable but also one of the more expensive pump models.
The best pump style depends on the design and layout of the hot water system. Qualified plumbers can advise on which style is most appropriate for a given application.
Installation
Proper installation is key to an effective and efficient hot water circulation system. Here are some important installation tips:
- The pump should be on the return line between the water heater and furthest hot water fixtures.
- Install a check valve near the water heater to prevent backflow through the pump.
- Insulate hot water supply and return lines to minimize heat loss.
- Install an aquastat or timer to control pump operation if using a standard pump.
- Place sensors at the end of hot water lines if using a demand-based pump.
- Make sure all plumbing connections are properly supported and leak-free.
Hiring a professional plumber is recommended for circulation pump installation. Correct pump sizing, proper pipe routing, and critical details like check valves and control settings need to be addressed during installation.
Maintenance
Regular maintenance helps ensure a hot water circulation pump provides reliable service over years of operation. Recommended maintenance includes:
- Annually check and clean pump strainers.
- Inspect pumps for leaks – repair or replace if found.
- Test and record pump operating currents – higher than normal currents can indicate issues.
- Check pipe insulation – repair or replace as needed.
- Inspect control sensors and settings on demand-based pumps.
- Flush sediment from the water heater per manufacturer recommendations.
- Lubricate circulator pumps with water-based lubricant per intervals suggested by the pump manufacturer.
Following the manufacturer’s maintenance guidelines for a specific circulation pump model is always recommended. Maintenance costs are low compared to the energy and cost savings hot water circulation pumps provide.
Cost of Hot Water Circulation Pumps
Hot water circulation pump costs include:
- Pump purchase price – $100 to $350 depending on size, type, features
- Installation cost – $200 – $500 for labor if installed by a professional
- Energy costs for operation – higher for standard pumps, lower for demand-based
- Maintenance – $100 – $300 per year for inspection, cleaning, lubrication, parts
Larger homes and buildings with more extensive plumbing systems may require larger, more expensive pumps. Overall costs can usually be recouped through energy savings in 1-3 years in homes with frequent hot water usage.
Estimated Hot Water Circulation Pump Costs
| Pump Type | Purchase Price | Installation Cost | Annual Energy Cost |
| Standard Pump | $150 | $300 | $200 |
| Demand-Based Pump | $350 | $500 | $75 |
Costs can vary significantly depending on the pump size, style, energy prices, and complexity of installation. Consult with plumbers to obtain price quotes for your specific application.
Benefits of a Hot Water Circulation Pump
Installing a hot water circulation pump provides several important benefits:
- Saves water by eliminating the need to run taps waiting for hot water
- Saves energy and money on water heating costs
- Provides convenience of instant hot water at fixtures
- Helps prevent scalding accidents by eliminating hot/cold spikes
- Extends life of water heater by keeping water at stable temperature
- Keeps hot water lines from freezing in cold climates
- Improves performance of low-flow plumbing fixtures
The recirculation system design, proper pump sizing, and regular maintenance are key factors to maximize these benefits in a residential or commercial building. An experienced plumber can help optimize the system.
Conclusion
Installing a dedicated hot water circulation pump can greatly improve the performance and efficiency of a building’s plumbing system. Selecting the right pump style and properly sizing it for the home or building ensures optimal energy savings and convenience benefits. While circulating pump systems require an initial investment, choosing the right pump and plumber to install it will provide many years of reliable hot water delivery with lower operating costs.