How to Fill Your Hot Water Heater

Park Model RV Tiny Home

Important - Read First

Do NOT turn on the hot water heater circuit until the tank is completely full of water.

Turning the heater on dry can overheat or permanently damage the heating elements. The hot water heater breaker is located in the main electrical panel, and you will see warning labels there for this exact reason. Follow the steps below carefully. It is very straightforward, but important to do this.

Step-by-Step Instructions

1. Connect the water

  • Connect your pipe or hose to the home’s main water inlet.

  • Turn the water on slowly.

2. Check for leaks

After the water is on, inspect the following areas:

  • Under the bathroom sink

    • Check where the water lines screw into the faucet.

  • Under the kitchen sink

    • Check the threaded connections at the shutoff valves and faucet lines.

You are mainly checking the screw-in connections. Even a slow drip matters, so make sure everything stays dry before continuing.

3. Let the system pressurize

  • Leave the water on and wait about 10 minutes.

  • This allows the hot water heater tank to fill.

4. Open a hot faucet

  • Go to the bathroom sink.

  • Turn the faucet fully to HOT, which is the red option.

5. Confirm the tank is full

  • If water flows from the hot side of the faucet, this confirms water is inside the hot water heater tank.

  • Once water is flowing normally, the tank should be full.

You do not need to turn on the kitchen sink or shower for this step. One hot faucet is enough to confirm the tank is filled.

6. Turn on the breaker and monitor

  • Once water flow from the hot side is confirmed, turn on the hot water heater breaker at the electrical panel.

  • Let the heater run for up to 5 minutes and monitor:

    • The breaker stays on

    • The water begins warming

If the water does not start warming after about 5 minutes:

  • Turn the breaker back off

  • Do not continue cycling power

  • Restart the process or contact your point of contact or a licensed plumber for assistance

Water Heater Access (Cavco Model Homes)

On most Cavco park model homes, the hot water heater is located:

  • On the side of the house

  • Opposite the main water inlet

  • Behind a rectangular exterior access panel

Important notes about the access panel:

  • The panel is a very snug fit

  • It is secured with square-drive screws

  • Removing it may require gently prying with a flat bar or crowbar

  • Take care not to damage the siding or panel edges

This access is not required to fill or activate the water heater. Nothing inside needs to be opened, adjusted, or switched for normal setup. The panel is only for service or inspection if needed.

Final Reminders

  • Nothing on the water heater itself needs to be turned on or adjusted during this process.

  • The most important rule is confirming the tank is full before applying power.

  • If anything feels off, stop and double-check before continuing.