Tankless coil water heaters are a popular option for providing on-demand hot water, especially in colder climates where boilers are commonly used. Unlike traditional tank-based systems, tankless coil heaters produce hot water as needed, which can be energy-efficient when used correctly.
However, there are ways to maximize their performance, reduce energy consumption, and lower your utility bills. This guide will cover practical tips and strategies for boosting the efficiency of your tankless coil water heater.
Adjust Boiler Settings for Optimal Temperature
The efficiency of a tankless coil water heater is closely tied to the performance of the boiler that supplies it. Ensure your boiler is set to the optimal temperature, typically around 140°F (60°C) for heating and hot water. If it’s set too low, the system may struggle to supply adequate hot water, while too high a setting wastes energy.
To maximize efficiency, consider installing an aquastat, a thermostat control that maintains water temperature within the coil, preventing overheating and saving energy.
Install a Mixing Valve to Stabilize Temperature
Adding a mixing valve to your tankless coil water heater can significantly improve both comfort and efficiency. Mixing valves help regulate water temperature by mixing cold and hot water as it exits the heater, which reduces the risk of scalding and provides more consistent temperatures.
With a mixing valve, you can set your boiler at a higher temperature without experiencing overly hot water at your taps. This setup ensures more efficient heating and minimizes the need for continuous adjustments.
Insulate Pipes to Reduce Heat Loss
Heat loss through pipes is one of the most common issues affecting water heater efficiency. Insulating your hot water pipes minimizes heat loss and ensures that hot water reaches your fixtures faster, reducing wasted water and energy.
Pipe insulation sleeves are easy to install and available at most hardware stores. By insulating pipes, you can maintain a more consistent water temperature and reduce the need to constantly reheat water.
Schedule Regular Boiler Maintenance
Tankless coil water heaters depend on a well-functioning boiler to perform efficiently. Over time, sediment, scale, and mineral buildup can accumulate within the boiler and the heating coil, reducing efficiency and heating capacity.
Regular maintenance—such as descaling, cleaning, and checking the burners—helps the boiler and coil operate at peak efficiency. Scheduling annual or biannual professional maintenance can prevent costly repairs, extend the life of the system, and maintain optimal heating performance.
Use Water-Saving Fixtures and Appliances
High-flow fixtures and appliances increase demand on your tankless coil water heater, requiring it to work harder and reducing its efficiency. Low-flow showerheads, faucets, and water-efficient appliances, such as dishwashers and washing machines, can significantly reduce hot water usage.
This not only saves water but also eases the load on your heating system, allowing it to operate more efficiently and use less energy overall.
Consider Installing a Tempering Tank
In colder climates, the cold water entering your tankless coil system can place a high demand on the boiler to bring it up to the desired temperature, especially during winter.
Installing a tempering tank, which pre-warms the cold water before it enters the tankless coil system, can help alleviate this. Tempering tanks use passive heat from the surrounding area to warm incoming water, which reduces the energy needed to bring it up to the desired temperature.
Limit Hot Water Demand During Peak Times
Running multiple hot water sources simultaneously, such as the shower, dishwasher, and washing machine, can strain the capacity of your tankless coil system and reduce its efficiency.
To avoid this, try to stagger hot water usage. For instance, run the dishwasher or washing machine at times when other hot water needs are low. This reduces demand on the system, helping it to operate more efficiently.
Install a Heat Recovery Ventilator (HRV)
If you live in a climate where cold incoming water significantly affects your system’s efficiency, consider a heat recovery ventilator (HRV). An HRV system captures heat from the boiler's exhaust gases and transfers it to the incoming cold water supply.
This pre-heats the water before it reaches the coil, which reduces the workload on the boiler and saves energy. HRVs can be particularly effective in reducing overall heating costs for tankless coil systems.
Upgrade to a High-Efficiency Boiler
Older boilers often consume more fuel and may not provide consistent heating to the tankless coil, reducing the water heater’s efficiency. Upgrading to a high-efficiency condensing boiler, which operates with greater fuel efficiency and less heat loss, can improve the overall performance of your tankless coil water heater.
Look for boilers with high annual fuel utilization efficiency (AFUE) ratings for optimal energy savings.
Install a Timer or Smart Control System
Tankless coil water heaters can benefit from a timer or smart control system that adjusts heating based on your usage patterns. For example, if your home typically requires hot water in the mornings and evenings, a timer can control the boiler’s heating cycles, limiting operation during low-demand hours.
Smart controls can also monitor usage and adjust settings automatically, further enhancing efficiency and convenience.
Final Thoughts
Tankless coil water heaters offer a practical and efficient solution for homes with existing boilers, providing hot water on demand without the need for a separate storage tank.
However, by implementing these efficiency-boosting strategies, you can further reduce energy consumption, improve water temperature stability, and maximize the performance of your heating system.
Regular maintenance, effective temperature management, and strategic upgrades can help ensure that your tankless coil water heater remains an energy-efficient and reliable source of hot water for years to come.
