Replacing a Mobile Home Water Heater: A Step-by-Step Guide
Choosing the Right Water Heater
When selecting a replacement water heater for your mobile home, it’s crucial to choose one specifically designed for mobile home use. These heaters must meet strict U.S. Department of Housing and Urban Development (HUD) standards, which ensure compliance with building codes and insurance requirements.
Mobile home water heaters typically have unique features, such as:
- Side-mounted cold water inlet
- Non-adjustable temperature-and-pressure relief (TPR) valve
- Smaller overall size than comparable standard units
- Sealed-combustion design if installed indoors
Water Heater Fuel Types
Mobile home water heaters can use various fuel sources, including:
- Gas: Propane or natural gas
- Electric: Requires a dedicated 240-volt circuit
- Fuel oil: Less common, often requiring conversion
Determining the Water Heater Location
The location of your mobile home water heater is important, especially for gas units. Gas water heaters installed inside the home, such as in closets or alcoves, must be sealed-combustion to prevent the mixing of intake and exhaust air. Gas water heaters located in exterior compartments can be standard gas units approved for mobile home use.
Before You Begin
Before starting the replacement process, ensure the following:
- Close the shutoff valves for both the cold water supply line and the gas supply line.
- Allow the water heater to cool completely.
Tools and Materials You’ll Need
Equipment / Tools:
- Garden hose
- Adjustable wrenches, pipe wrenches, or tongue-and-groove pliers
- Drill and attachments for driving screws or anchors
- Drip pan and drain (as needed)
Materials:
- New water heater of appropriate size
- Fasteners for tank brackets or strapping (as needed)
- Sheet metal screw
- Discharge tube for TPR valve (as needed)
- Thread-seal tape for plumbing connections
- Gas-rated thread-seal tape for gas connections
- Gas-leak testing solution
Step-by-Step Installation Instructions
1. Drain the Tank
- Connect a garden hose to the drain valve on the water heater tank.
- Extend the hose to a suitable drainage point and open the valve to drain the water.
- Open the TPR valve to allow air into the system and prevent suction.
- Close the drain valve and disconnect the hose when the tank is empty.
2. Remove the Old Water Heater
- Disconnect the flexible gas line from the gas control valve.
- Disconnect the hot and cold water lines from the tank outlet and inlet, respectively.
- Disconnect the vent duct from the draft hood on the tank.
- Remove the tank from the water heater compartment by unscrewing the strapping or bracket fasteners securing it.
3. Install a Drip Pan
- If necessary, install a corrosion-resistant drip pan and drain for the new water heater. Reuse an existing pan if it’s in good condition and appropriately sized.
4. Install the TPR Valve
- Install the new TPR valve onto the new water heater, following the manufacturer’s instructions.
5. Place the New Water Heater
- Fit the new water heater into place on the drip pan, ensuring it aligns with the existing gas supply, water piping, and vent duct.
- Secure the tank to the wall and floor using the provided brackets or strapping, as required by local building codes.
6. Complete the Vent Connection
- Install the draft hood onto the new heater tank, as directed by the manufacturer.
- Fit the vent duct over the outlet on the draft hood and secure it with a sheet metal screw.
7. Install the TPR Discharge Tube
- Install a copper or CPVC pipe onto the TPR valve, directing it to the home’s exterior. Reuse the old discharge tube if it’s suitable and in good condition.
8. Connect the Water Lines
- Connect the cold water supply pipe to the cold water inlet on the heater tank using an approved supply connector and thread-seal tape.
- Connect the hot water outlet on the tank to the hot water piping with an approved connector.
9. Connect and Test the Gas Line
- Connect the gas supply tube to the gas control valve as per the manufacturer’s instructions, using gas-rated thread-seal tape.
- Turn on the gas supply and test all gas connections with a gas-leak testing solution to ensure there are no leaks.
10. Fill the Tank
- Confirm the drain valve is closed and turn on the cold water supply to begin filling the tank.
- Open the hot water tap at the nearest faucet in the house to allow air to escape.
- Close the faucet when water flows freely from the tap, indicating a full tank.
11. Check the Installation and Start the Tank
- Ensure all connections are secure and there are no leaks.
- Start the pilot light on the heater according to the manufacturer’s directions.
Troubleshooting Common Problems
Water Heater Not Heating Water:
- Check if the gas or electric supply is turned on.
- Inspect the TPR valve for leaks or damage.
- Ensure the pilot light is lit (for gas heaters).
Water Heater Leaking:
- Tighten any loose connections or replace damaged components.
- Check the TPR valve for proper operation.
Insufficient Hot Water:
- Increase the water heater temperature setting.
- Check for sediment buildup in the tank, which can reduce heating efficiency.
FAQs
What is the standard-size water heater for a mobile home?
30-gallon water heaters are common, with 40-gallon tanks also available. Smaller 28-gallon tanks may suffice for one person, but anything smaller is designed for specific uses.
How long does a mobile home hot water heater last?
Typically 8 to 12 years, similar to traditional home water heaters.
Can you use a tankless water heater in a mobile home?
Yes, mobile home-compatible tankless water heaters exist. Consider an electric tankless water heater for capacities over 30 gallons or a gas tankless heater that uses propane, as mobile homes typically don’t have access to natural gas.
