Replacing a tankless water heater can be a daunting task, but if you follow a few simple steps, you can get the job done quickly and efficiently. Before you start, it’s imperative to gather the necessary tools and materials, such as a new water heater, a wrench, a screwdriver, and a pair of pliers. Once you have everything you need, you can begin the replacement process.
To replace a tankless water heater, you must first disconnect the old unit from the water and gas supply. Once the old unit is disconnected, you can remove it from its mounting bracket and install the new unit in its place. Be sure to connect the new unit to the water and gas supply and turn on the water and gas to test the unit for leaks. It’s also essential to check the manufacturer’s instructions for specific installation requirements, as some models may require additional steps.
Replacing a tankless water heater can be a simple task with a little research and preparation. By following these steps, you can replace your old unit quickly and efficiently and enjoy the benefits of a new tankless water heater.
Preparation and Safety Precautions
Safety Measures
Before embarking on this task, safety should be your utmost priority. Here are some crucial precautions to observe:
- Turn off gas or electricity: Locate the gas or electric shut-off valve and turn it off to prevent any energy flow to the water heater.
- Drain the water: Connect a hose to the drain valve located at the bottom of the water heater and open a hot water tap to drain the tank.
- Disconnect the water lines: Shut off the water supply valves connected to the cold and hot water lines. Then, disconnect the lines from the water heater.
- Wear protective gear: It’s advisable to wear gloves, safety glasses, and sturdy shoes while handling the water heater and its components.
Tools and Materials
Gather the following tools and materials to facilitate the replacement process:
| Item | Description |
|---|---|
| New tankless water heater | Replacement unit compatible with your gas or electric system |
| Wrenches | Adjustable and pipe wrenches for tightening and loosening nuts |
| Screwdrivers | Phillips and flathead screwdrivers for assembling and disassembling |
| Plumber’s tape | Used to seal connections and prevent leaks |
| Electrical wire | For connecting the water heater to the electrical system (if applicable) |
Planning the Installation
- Choose a suitable location: Tankless water heaters can be installed indoors or outdoors. Select a location that allows adequate ventilation and allows for easy access to plumbing and electrical connections.
- Consider the flow rate: Determine the required flow rate for your household to ensure the water heater meets your hot water needs.
- Prepare the mounting surface: Mount the water heater on a sturdy wall or floor that can support its weight and provide stability.
Shutting Off Utilities and Draining the Heater
Step 1: Turn Off Water and Gas Supply
* Locate the main water shut-off valve, typically found near the water meter or in the basement. Turn it clockwise to close the valve completely.
* If your water heater is gas-powered, turn off the gas supply by locating the shut-off valve on the gas line leading to the heater. Turn the valve clockwise to close it.
Step 2: Open Faucets to Drain Water
* Open all hot water faucets in the house, including sinks, tubs, and showers, to drain the hot water from the system.
* You may notice some air coming out of the faucets as the water drains. This is normal.
* Continue running the faucets until the water stops flowing or becomes cold. This indicates that the system is mostly drained.
Caution: Do not open the pressure relief valve to drain the heater, as this could cause damage to the valve or the heater itself.
Step 3: Remove Drain Plug
* Locate the drain plug at the bottom of the tankless water heater. It is typically a small, round plug. Use a wrench or pliers to unscrew the plug.
* As you remove the plug, be prepared for a small amount of water to leak out.
* Allow the water to drain from the bottom of the heater until it stops flowing.
Disconnecting the Water Lines
Before detaching the water lines, ensure all gas and power sources are turned off. Wear proper safety gear, including gloves and safety glasses, to protect yourself from potential hazards.
Locate the isolation valves on the cold water inlet and hot water outlet lines. Close these valves to prevent water from flowing into or out of the tankless water heater.
Draining the Water Lines
Connect a hose to the drain valve on the tankless water heater. Open the drain valve to release the remaining water in the system. Allow the water to drain completely into a bucket or drain pan.
Remove the hose from the drain valve and close the valve.
Disconnecting the Water Lines
Using an adjustable wrench, carefully loosen the nuts connecting the water lines to the tankless water heater. Do not overtighten or use excessive force, as this could damage the lines or the tankless water heater itself.
Once the nuts are loose, gently pull the water lines away from the tankless water heater. If necessary, use a pry bar to gently pry the lines loose. Be careful not to damage the water lines or the surrounding components.
Remove any remaining fittings or connectors from the water lines. Ensure that the ends of the water lines are clean and free of debris before connecting them to the new tankless water heater.
| Water Line | Notes |
|---|---|
| Cold Water Inlet | Locate above the tankless water heater |
| Hot Water Outlet | Locate below the tankless water heater |
| Drain Valve | Used to empty remaining water |
Removing the Old Water Heater
Before replacing your water heater, you must first remove the old one. Here are the steps to do so:
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Turn off the water supply. This is essential for safety reasons. Locate the water supply valve and turn it clockwise to shut off the water.
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Open a hot water tap to relieve any pressure. This will allow any remaining water in the system to drain out.
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Disconnect the water lines. Use a wrench to loosen the nuts that connect the water lines to the water heater. Once the nuts are loose, pull the water lines off the heater.
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Drain the water heater. This can be a challenging step, so exercise caution. Place a bucket or large container beneath the water heater’s drain valve. Open the valve and allow the water to drain. Depending on the size of the water heater, this can take anywhere from 15 minutes to an hour.
Tip To speed up the draining process, you can use a submersible pump to extract water from the water heater. -
Disconnect the gas line (if applicable). If you have a gas water heater, you will need to turn off the gas supply valve and disconnect the gas line from the heater.
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Disconnect the electrical wires. This should only be done by a qualified electrician. Carefully remove the safety cover and disconnect the wires.
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Remove the water heater. Once the water heater is disconnected, you can carefully remove it from its location. This may require assistance if the heater is heavy.
Installing the New Water Heater Mount
1. Remove the Old Mount: Look for screws or bolts holding the old mount in place. Remove them and carefully detach the mount from the wall or studs.
2. Locate the New Mount Placement: Determine the optimal location for the new mount to support the weight of the tankless water heater. Mark the studs or wall if needed.
3. Secure the New Mount: Align the new mount with the marked location and use screws or bolts to securely attach it to the studs or wall. Ensure the mount is level and firmly fastened.
4. Adjust the Height: If the mount is adjustable, verify the recommended height for your water heater model and adjust it accordingly. This will ensure the water heater is at the correct elevation.
5. Finalize the Mount Installation: Double-check all connections and ensure the mount is stable and securely in place. Tighten any bolts or screws as necessary. Refer to the manufacturer’s instructions for specific mounting requirements and any additional steps.
Table: Mount Installation Tips
| Tip |
|---|
| Use a level to ensure proper alignment during installation. |
| Secure the mount with high-quality screws or bolts that are rated for the weight of the water heater. |
| Follow the manufacturer’s instructions carefully for precise mount placement and height adjustment. |
Connecting the Water Lines
Connect the cold water supply line to the inlet valve on the tankless water heater. Use a wrench to tighten the connection securely.
Connect the hot water outlet line to the outlet valve on the tankless water heater. Again, use a wrench to tighten the connection securely.
Connecting the Gas Supply
Locate the gas supply line and connect it to the gas inlet valve on the tankless water heater. Use a wrench to tighten the connection securely.
Detailed Instructions for Gas Supply Connection:
- Shut off the gas supply valve. This is usually located near the gas meter or where the gas line enters your property.
- Apply pipe thread sealant to the threads of the gas inlet valve. This will help prevent gas leaks.
- Connect the gas line to the inlet valve. Use a wrench to tighten the connection securely, following the manufacturer’s torque specifications.
- Check for gas leaks. Use a soapy water solution to check for leaks around the connection. If you see bubbles forming, there is a leak. Tighten the connection further or call a qualified professional for assistance.
- Turn on the gas supply valve. Open the valve slowly and check for leaks again.
- Properly purge the gas line:
- Purge the gas from the line. Open a hot water tap and let the water flow for a few minutes to purge the air from the gas line.
- Light the pilot light or ignite the burner. Follow the manufacturer’s instructions for lighting the pilot light or igniting the burner.
- Check for proper operation. Once the pilot light is lit or the burner is ignited, check the flame to ensure it is stable and blue. If the flame is unstable or yellow, there may still be air in the gas line. Continue purging until the flame is stable and blue.
Testing and Inspecting the New Heater
1. Check for Leaks
Turn on the water supply to the heater and inspect for any leaks at the connections. Tighten any loose fittings if necessary.
2. Test the Temperature
Turn on the hot water tap and run it for a few minutes. Check the temperature using a thermometer to ensure it reaches the desired level.
3. Verify Flame Quality
If the heater uses gas, observe the flame through the sight glass. It should be a steady, blue flame. Yellow flames indicate incomplete combustion, which can lead to problems.
4. Check the Exhaust
Ensure that the exhaust flue is properly connected and there are no blockages or leaks. Proper exhaust is crucial for safety and efficiency.
5. Test the Controls
Test the thermostat and other controls to make sure they are functioning correctly. Set different temperatures and observe the heater’s response.
6. Monitor Pressure
Check the water pressure gauge or consult the heater’s manual to ensure it is within the recommended range. Low pressure can affect performance, while high pressure can cause leaks.
7. Comprehensive Troubleshooting
If you encounter any issues during testing, refer to the troubleshooting guide in the heater’s manual or consult a qualified technician. Common problems include:
| Symptom | Possible Cause |
|---|---|
| No hot water | – Faulty thermostat – Blocked filter – Gas supply issue |
| Fluctuating water temperature | – Faulty temperature sensor – Water flow issues – Scale buildup |
| Leaks | – Loose fittings – Damaged gaskets – Cracks in the tank |
Troubleshooting Common Installation Issues
1. Water Leaking from the Heater
Check the water supply lines and fittings for tightness. If leaking persists, inspect the heater’s internal components, such as the heat exchanger or pressure relief valve.
2. No Hot Water
Confirm that the power supply is active and the gas valve is open. Check the temperature setting and water flow rate. If these are correct, examine the heating element or gas burner for any issues.
3. Water Temperature Fluctuating
Adjust the temperature setting on the heater. Inspect the flow sensor to ensure it’s clean and functioning properly. Check for any blockages or kinks in the water lines.
4. Low Water Pressure
Increase the water flow rate to the heater. Check for any restrictions in the water supply lines or aerators. Clean the filter screens on the inlet and outlet ports.
5. Gas Leaks
Never attempt to fix a gas leak yourself. Call a qualified technician immediately. Ensure the gas valve is closed and the area is well-ventilated.
6. Error Codes
Refer to the manufacturer’s manual for specific error code meanings. These codes indicate a specific problem with the heater that requires attention.
7. Combustion Problems
Inspect the exhaust vent pipe for any obstructions. Ensure the vent pipe is properly sized and terminated outdoors. Check the gas burner for any blockages or debris.
8. Electrical Faults
Verify that the power supply is providing the correct voltage and amperage. Check all electrical connections within the heater for tightness and security. If electrical issues persist, contact a licensed electrician.
| Electrical Faults Troubleshooting Steps |
|---|
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Maintenance and Safety Tips for Tankless Water Heaters
Regular Maintenance
To ensure optimal performance and longevity, it’s crucial to schedule regular maintenance for your tankless water heater. Follow these steps:
- Flush the unit annually: Remove sediment and mineral buildup by flushing the heater with a 5% vinegar solution.
- Inspect the anode rod: This rod sacrifices itself to protect the tank, so inspect it every few months and replace it when it’s 60% consumed.
- Clean the filter: Replace or clean the filter screen to prevent debris from entering the system.
Safety Precautions
Tankless water heaters use gas or electricity as a fuel source, so safety precautions are essential:
- Gas leak detection: Install a gas detector near the unit to alert you to potential leaks.
- Electrical wiring: Ensure that all electrical connections are secure and meet code requirements.
- Water pressure: Maintain the proper water pressure range to prevent damage to the unit.
Troubleshooting Tips
If you’re experiencing issues with your tankless water heater, consider these troubleshooting tips:
- No hot water: Check the gas or electricity supply, and ensure that the unit is powered on.
- Fluctuating water temperature: Adjust the temperature setting or inspect the flow sensor for sediment buildup.
- Leaking water: Inspect the unit for any cracks, loose fittings, or leaks from the drain valve.
Advanced Maintenance: Replacing the Ignition Assembly
The ignition assembly is a critical component that sparks the flame, and over time, it may require replacement due to corrosion or wear. This process is not recommended for DIYers and should be performed by a qualified technician:
Step 1: Power down and isolate the unit
Turn off the gas or electricity supply and close the water shut-off valves.
Step 2: Remove the ignition assembly
Locate the ignition assembly, typically near the burner, and disconnect any electrical wires or gas lines.
Step 3: Install the new ignition assembly
Connect the new assembly and tighten all fittings. Ensure proper electrical connections or gas line tightness.
Step 4: Test the unit
Turn on the gas or electricity supply and open the water shut-off valves. Ignite the unit and check for proper operation.
Step 5: Reset safety features
If the unit has resettable safety features, such as a high-temperature cut-off, you may need to reset them after replacing the ignition assembly.
Materials Needed
– New tankless water heater
– Gas line valve wrench
– Pipe wrench
– Screwdriver
– Electrical tape
– Plumber’s putty
Tools Needed
– Adjustable wrench
– Screwdriver
– Drill
– Hacksaw
– Level
Steps
1. Shut off the gas and water supply to the old water heater.
2. Disconnect the gas line and water lines from the old water heater.
3. Remove the old water heater from the wall or floor.
4. Install the new water heater on the wall or floor.
5. Connect the gas line and water lines to the new water heater.
6. Turn on the gas and water supply to the new water heater.
7. Check for leaks.
8. Adjust the temperature setting on the new water heater.
9. Turn on the hot water faucets in your home to flush out any air from the lines.
10. Enjoy your new tankless water heater!
Frequently Asked Questions About Tankless Water Heater Replacement
Do I need to hire a plumber to replace my tankless water heater?
While it is possible to replace a tankless water heater yourself, it is recommended that you hire a plumber if you are not comfortable working with gas and water lines.
How much does it cost to replace a tankless water heater?
The cost to replace a tankless water heater will vary depending on the size and brand of the water heater, as well as the cost of labor in your area. However, you can expect to pay between $1,000 and $2,500 for a new tankless water heater and installation.
How long does it take to replace a tankless water heater?
A professional plumber can usually replace a tankless water heater in about 2-4 hours. However, if you are replacing the water heater yourself, it may take you longer.
What are the benefits of tankless water heaters?
Tankless water heaters offer a number of benefits over traditional water heaters, including:
- Endless hot water: Tankless water heaters heat water on demand, so you never have to worry about running out of hot water.
- Energy efficiency: Tankless water heaters only heat water when you need it, so they are more energy efficient than traditional water heaters.
- Space saving: Tankless water heaters are much smaller than traditional water heaters, so they can be installed in tight spaces.
- Longer lifespan: Tankless water heaters have a longer lifespan than traditional water heaters, so you can save money on replacement costs over time.
What are the drawbacks of tankless water heaters?
While tankless water heaters offer a number of benefits, there are also some drawbacks to consider before purchasing one:
- Higher upfront cost: Tankless water heaters are more expensive to purchase and install than traditional water heaters.
- Reduced flow rate: Tankless water heaters may not be able to provide the same flow rate as a traditional water heater, so you may experience a decrease in water pressure at your fixtures.
- Cold water sandwiches: If you use a lot of hot water in a short period of time, you may experience a “cold water sandwich” effect, where the water temperature drops temporarily before it heats up again.
- Maintenance: Tankless water heaters require more maintenance than traditional water heaters, so you will need to budget for regular maintenance costs.
How to Replace a Tankless Water Heater
Replacing a tankless water heater can be a daunting task, but it is not impossible. With the right tools and a little bit of know-how, you can get the job done in a few hours.
Here are the steps on how to replace a tankless water heater:
- Turn off the water supply to the water heater.
- Turn off the gas supply to the water heater.
- Disconnect the water lines from the water heater.
- Disconnect the gas line from the water heater.
- Remove the old water heater from the wall or ceiling.
- Install the new water heater.
- Connect the water lines to the new water heater.
- Connect the gas line to the new water heater.
- Turn on the water supply to the water heater.
- Turn on the gas supply to the water heater.
Once you have completed these steps, your new tankless water heater should be up and running.
People Also Ask
How much does it cost to replace a tankless water heater?
The cost of replacing a tankless water heater varies depending on the make and model of the water heater, as well as the cost of labor.
How long does it take to replace a tankless water heater?
Replacing a tankless water heater typically takes about 2-3 hours.
Can I replace a tankless water heater myself?
Yes, you can replace a tankless water heater yourself. However, it is important to have the proper tools and knowledge before attempting this task.
