Installing a tankless hot water heater can be a great way to save energy and money, and it can also provide you with an endless supply of hot water. However, tankless water heaters can be more expensive to purchase and install than traditional water heaters, so it’s important to weigh the pros and cons before making a decision.
If you’re considering installing a tankless water heater, it’s important to do your research and choose the right model for your needs. There are a few different types of tankless water heaters available, so it’s important to compare the features and benefits of each type before making a decision. You should also consider the size of your home and the number of people who live there when choosing a tankless water heater. Finally, it’s important to hire a qualified plumber to install your tankless water heater to ensure that it is installed properly and safely.
Planning and Preparation
1. Determine Your Hot Water Needs
To size a tankless water heater appropriately, you need to calculate your peak hot water demand in gallons per minute (GPM). This involves considering the maximum number of simultaneous fixtures that will be used, such as showers, sinks, and washing machines. Refer to the table below for average flow rates of typical fixtures:
| Fixture | Flow Rate (GPM) |
|---|---|
| Showerhead | 2-3 |
| Kitchen sink | 1-2 |
| Bathroom sink | 0.5-1 |
| Washing machine | 2-3 |
Once you have determined your peak demand, round it up to the nearest whole number to ensure you have adequate capacity. For example, if your peak demand is 5.5 GPM, you would choose a water heater with a minimum capacity of 6 GPM.
2. Consider Gas Supply and Electrical Requirements
Tankless water heaters require a gas connection for fuel and an electrical connection for power. Determine the type of gas available at your property (natural gas or propane) and ensure your chosen heater is compatible. Check the electrical requirements of the heater and ensure you have the appropriate wiring and circuit breaker capacity.
Choosing the Right Location
Selecting the optimal location for your tankless hot water heater is crucial for ensuring efficient operation and extending its lifespan. Here are some key considerations:
Proximity to Water Source
The tankless heater should be installed within a short distance of the cold water supply pipe to minimize pressure drop and ensure adequate water flow. A distance of 1-2 feet is generally recommended.
Proper Ventilation
Tankless heaters produce significant amounts of exhaust gases, so proper ventilation is essential. The unit should be installed in a well-ventilated area, such as a basement, garage, or utility room, with sufficient air circulation to prevent the buildup of harmful fumes.
Gas Vent and Water Heater Clearance
For gas-fired tankless heaters, the following minimum clearances must be maintained around the vent and heater itself:
| Clearance | Requirement |
|---|---|
| From Vent Terminations to Combustible Materials | 12 inches |
| From Gas Meter or Regulator to Heater | 36 inches |
| From Heater to Combustible Materials (Side and Back) | 6 inches |
| From Heater to Combustible Materials (Front) | 18 inches |
Installing the Gas Line
Sizing the Gas Line
The size of the gas line needed depends on the BTU input of the tankless water heater. The BTU input is the amount of energy the heater uses per hour. The larger the BTU input, the larger the gas line that is needed. The following table provides a guide to the minimum gas line size for different BTU inputs:
| BTU Input | Gas Line Size |
|---|---|
| Up to 150,000 | 1/2 inch |
| 150,000 to 200,000 | 3/4 inch |
| Over 200,000 | 1 inch |
Installing the Gas Line
Once the gas line size has been determined, the line can be installed. The following steps should be followed:
1. Shut off the gas supply to the area where the tankless water heater will be installed.
2. Open a nearby gas valve to release any gas pressure in the line.
3. Cut the gas line at the desired location for the tankless water heater.
4. Install a gas shut-off valve on the gas line.
5. Connect the gas line to the tankless water heater.
6. Turn on the gas supply and check for leaks.
Testing the Gas Line
Once the gas line has been installed, it should be tested for leaks. The following steps should be followed:
1. Turn on the gas supply to the tankless water heater.
2. Apply a soapy water solution to the gas line connections.
3. Check for any bubbles forming. If bubbles are present, there is a leak.
4. Tighten the gas line connections and retest for leaks.
Running the Electrical Wiring
Installing the electrical wiring for your tankless water heater requires careful planning and attention to safety precautions. First, determine the amperage and voltage requirements of your water heater and ensure your electrical panel can handle the load. Check your local building codes for specific requirements and permits.
Next, route the wires from the electrical panel to the location of the water heater. Use the shortest and most direct path possible, avoiding any potential hazards. Run the wires through conduit to protect them from damage and moisture. Ensure the conduit is properly grounded.
Connect the wires to the water heater following the manufacturer’s instructions. Use the appropriate wire nuts and electrical tape to ensure secure connections. Be sure to tighten all terminals securely and double-check all connections before turning on the power.
Table: Electrical Wiring Standards for Tankless Water Heaters
| Voltage | Amperage | Wire Size | Conduit Size |
|---|---|---|---|
| 120 V | 15 A | 14 AWG | 1/2 inch |
| 240 V | 30 A | 10 AWG | 3/4 inch |
| 240 V | 50 A | 6 AWG | 1 inch |
Note: Consult with a qualified electrician for any electrical work or if you are not familiar with electrical installations.
Connecting the Venting
Venting is crucial for ensuring the safe and efficient operation of your tankless water heater. It helps exhaust combustion gases and bring in fresh air to support the combustion process. Here’s a detailed guide on how to connect the venting:
1. Determine Vent Type
Locate the venting requirements in your water heater’s manual and determine whether a B-vent or an exhaust vent is recommended. B-vents are typically used for direct vent water heaters, while exhaust vents are used for atmospheric vent water heaters.
2. Choose Venting Materials
Select the appropriate venting materials based on the vent type. For B-vents, use double-walled galvanized steel pipes, connectors, and fittings. For exhaust vents, use single-walled stainless steel or aluminum pipes, connectors, and fittings.
3. Plan the Vent Route
Determine the optimal route for the venting system, keeping in mind the following considerations:
- Maintain a straight path with minimal bends and elbows.
- Avoid routing the vent through areas with high humidity or condensation.
- Ensure a minimum clearance of 12 inches from combustible materials.
4. Install the Vent Termination
Install the vent termination at the end of the vent system, ensuring it is located properly according to the manufacturer’s specifications. The termination cap should be weatherproof and designed to prevent downdrafts or back-drafting.
5. Assemble and Connect the Venting
Assemble the venting components as per the manufacturer’s instructions. Use pipe sealant or thread tape to create airtight connections. Ensure all joints are properly tightened and securely fastened. Once assembled, connect the venting system to the water heater and fasten the connections using the provided clamps or brackets.
Mounting the Tankless Heater
Before mounting the tankless heater, gather the necessary tools and materials, including a level, drill, screwdriver, mounting brackets, and screws. Follow these steps for secure and proper installation.
1. Safety First
Turn off the gas and water supply to the installation area. If disconnecting any electrical components, ensure they are properly de-energized.
2. Choose the Mounting Location
Select a suitable location for the heater, ensuring there is ample space for access and ventilation. Consider factors such as gas lines, water pipes, and electrical connections.
3. Mark the Mounting Holes
Use a level and pencil to mark the positions of the mounting holes on the wall. Align the heater’s mounting bracket with the marks and ensure it is level.
4. Drill the Mounting Holes
Using an appropriate drill bit, drill holes at the marked locations. The hole size will depend on the diameter of the provided screws.
5. Install the Mounting Brackets
Insert the provided screws into the mounting holes and secure the mounting brackets to the wall. Tighten the screws firmly, ensuring the brackets are securely fastened.
6. Mount the Tankless Heater
Carefully lift the tankless heater onto the mounting brackets. Align the screw holes on the heater with those on the brackets and thread in the provided bolts. Tighten the bolts gradually, ensuring the heater is securely fixed without over-tightening.
| Step | Description |
|---|---|
| 1 | Check the manufacturer’s instructions for specific torque specifications. |
| 2 | Use a torque wrench or a hex key with a torque limiter to prevent damage. |
| 3 | Distribute the torque evenly across all mounting bolts to ensure a secure and level installation. |
Connecting the Water Lines
This step is crucial for ensuring a steady and reliable flow of hot water to your faucets and appliances. Here’s how to connect the water lines to your tankless hot water heater:
1. Shut Off Existing Water Supply
Locate the main water supply valve and turn it off to prevent flooding while you work.
2. Install Isolation Valves
On both the cold and hot water lines, install isolation valves that will allow you to shut off the water supply to the heater when necessary, such as for repairs or maintenance.
3. Cut the Pipes
Use a tubing cutter to make clean cuts on the hot and cold water lines where you want to connect the heater.
4. Connect the Cold Water Inlet
Attach the flex hose to the cold water inlet of the heater and secure it with a hose clamp. Tighten the hose clamp using a wrench.
5. Connect the Hot Water Outlet
Similarly, connect the flex hose to the hot water outlet of the heater and secure it with a hose clamp.
6. Install Unions
Attach unions to the end of the flex hoses connecting to the water lines. Unions allow you to easily disconnect the heater for maintenance or replacement.
7. Sweat Copper Pipes (Optional)
If you’re using copper water lines, you’ll need to solder the copper pipes to the flex hoses. Apply flux to the connection points, insert the copper pipe, and heat the joint with a torch while applying solder. Repeat this process for both the cold and hot water lines. Ensure the solder joints are clean and free of any leaks.
| Type of Connection | Materials Needed | Steps |
|---|---|---|
| Flex Hose Connection | Flex hoses, hose clamps, unions | Attach flex hoses to the heater inlets and outlets, secure with hose clamps, and install unions. |
| Copper Pipe Connection | Copper pipes, solder, flux, torch | Cut copper pipes, apply flux, insert into flex hoses, and heat with a torch while applying solder. |
Final Testing and Commissioning
Once the tankless water heater is installed, it’s important to perform thorough testing and commissioning to ensure it operates safely and efficiently.
1. Water Supply and Drainage Checks
Verify that the incoming water supply is open and at adequate pressure. Ensure that the drain line is properly connected and flowing freely.
2. Gas Line Check
Turn on the gas supply and check for leaks using a soap solution. All gas connections should be tight and secure.
3. Electrical Connection Check
Double-check all electrical connections to ensure they are secure and meet the manufacturer’s specifications.
4. Water Temperature Adjustment
Turn on the hot water faucet and adjust the temperature setting on the heater to the desired level.
5. Flow Rate Test
Run hot water through multiple fixtures simultaneously to test the heater’s ability to maintain the desired flow rate and temperature.
6. Leak Detection
Visually inspect the heater and all connections for any signs of leaks. Tighten any loose fittings if necessary.
7. Reset Temperature Limit
As a safety measure, reset the temperature limit switch located on the heater if it has been tripped.
8. Combustion Analysis (Optional)
For optimal performance and efficiency, consider hiring a qualified technician to perform a combustion analysis. This involves measuring the combustion gases to ensure proper air-to-fuel ratio and minimize emissions.
| Step | Description |
|---|---|
| 1. Disconnect gas and electrical connections. | Ensure safety before starting. |
| 2. Remove the water supply lines. | Drain the remaining water. |
| 3. Unbolt the heater from the wall. | Use a socket wrench or adjustable spanner. |
| 4. Lift the heater off the wall bracket. | Be careful not to damage the heater or surrounding area. |
Maintenance and Troubleshooting
Regular Maintenance
Regular maintenance is crucial for the longevity of your tankless hot water heater. Follow these steps:
Troubleshooting Common Issues
No Hot Water
Water Temperature Fluctuates
Unusual Noises
Error Codes
High Energy Consumption
Tips for Energy Efficiency
Tankless water heaters can save energy by only heating water on-demand, but there are additional steps you can take to maximize energy efficiency:
1. Reduce Water Flow
Install low-flow showerheads and faucets to reduce water consumption, which in turn reduces energy use. Aim for showerheads with a flow rate of 2.5 gallons per minute or less.
2. Insulate Hot Water Lines
Insulating hot water lines prevents heat loss from the pipes, reducing the amount of energy required to heat water.
3. Use a Recirculating Pump
If you have long hot water lines, a recirculating pump can continuously circulate hot water back to the tankless heater, eliminating wait time for hot water.
4. Set the Temperature Lower
Lower the temperature setting on your tankless water heater to the lowest comfortable level, typically around 120-130°F.
5. Use a Timer or Occupancy Sensor
Install a timer or occupancy sensor to turn off the tankless water heater during periods of non-use, such as at night or when you’re away.
6. Consider a Solar Tankless Heater
If you have adequate sunlight, a solar tankless water heater can significantly reduce or eliminate energy consumption.
7. Shut Off the Gas Supply
Turn off the gas supply to the tankless water heater when you’re away on vacation or for extended periods of non-use.
8. Regular Maintenance
Regularly inspect and maintain your tankless water heater according to the manufacturer’s instructions to ensure optimal performance and efficiency.
9. Use a Demand Limiter
A demand limiter can restrict the maximum flow rate of hot water, preventing excessive energy consumption.
10. Monitor Your Energy Consumption
Track your energy usage with a smart meter or energy monitoring device to identify areas where you can make additional energy-saving adjustments.
| Tip | Energy Savings |
|---|---|
| Reduce Water Flow | Up to 20% |
| Insulate Hot Water Lines | Up to 15% |
| Use a Recirculating Pump | Up to 10% |
How to Install a Tankless Hot Water Heater
Installing a tankless hot water heater is a great way to save energy and money. Tankless water heaters heat water on demand, so you’re not constantly heating a large tank of water that you may or may not use. This can save you up to 30% on your energy bills. Tankless water heaters are also more compact than traditional water heaters, so they can be installed in smaller spaces.
Before You Start
Before you begin installing a tankless hot water heater, you will need to gather a few tools and materials. You will need:
* A tankless hot water heater
* A gas or electric supply line
* A water supply line
* A drain line
* A vent pipe
* A shut-off valve
* Safety glasses
* Gloves
* Wrench
* Screwdriver
* Drill
* Level
Installation Instructions
1. Shut off the gas or electricity to your home.
2. Turn off the water supply to your home.
3. Open a faucet to release any remaining water pressure in the pipes.
4. Disconnect the old water heater from the gas or electric supply line, the water supply line, and the drain line.
5. Remove the old water heater from its location.
6. Install the new tankless water heater in the same location as the old water heater.
7. Connect the gas or electric supply line to the tankless water heater.
8. Connect the water supply line to the tankless water heater.
9. Connect the drain line to the tankless water heater.
10. Vent the tankless water heater according to the manufacturer’s instructions.
11. Turn on the gas or electricity to your home.
12. Turn on the water supply to your home.
13. Open a faucet and allow the water to run until it is hot.
14. Check for leaks.
People Also Ask
What size tankless water heater do I need?
The size of tankless water heater you need will depend on the number of people in your household and the amount of hot water you use. A general rule of thumb is to get a water heater that can produce about 1 gallon of hot water per minute per person. So, for a family of four, you would need a water heater that can produce about 4 gallons of hot water per minute.
How much does it cost to install a tankless water heater?
The cost of installing a tankless water heater will vary depending on the size of the water heater, the complexity of the installation, and the location of your home. However, you can expect to pay between $1,000 and $2,500 for the installation. You can save money on the installation by doing it yourself, but it is important to note that tankless water heaters are complex appliances and it is important to have them installed by a qualified professional.
What are the benefits of a tankless water heater?
There are many benefits to installing a tankless water heater, including:
- Energy efficiency – Tankless water heaters only heat water when you need it, so you’re not constantly heating a large tank of water that you may or may not use. This can save you up to 30% on your energy bills.
- Compact size – Tankless water heaters are more compact than traditional water heaters, so they can be installed in smaller spaces.
- Endless hot water – Tankless water heaters can provide an endless supply of hot water, so you never have to worry about running out of hot water.
- Long lifespan – Tankless water heaters have a longer lifespan than traditional water heaters, so you can expect to get years of trouble-free operation.
