If the water does not stay hot and the jets blow cold, the first thing to check is what the in line heater is designed to do. It maintains the temperature of the hot water you filled with; it does not heat a cold fill, and it runs only while the hydro pump is running. So the tub does not heat the water on its own. Your home water heater sets the starting temperature, and the in line heater holds it steady during the hydro massage. If the water cools down while you soak with the hydro off, that is expected. If it cools while the hydro is running, the next things to check are whether your tub has a hydro package at all and whether the heater is plugged into the right port on the control box.

Likely Causes

• The tub was filled with lukewarm water or soaked without the hydro running, so the heater had nothing to maintain or was not on. The in line heater guide explains the design.
• The tub is a soaker or air only model, which has no in line heater. The therapy package cheat sheet lists what each package includes.
• The heater is plugged into the wrong port on the control box, or on Hydro plus Hydro Foot builds the foot pump is not running, since the heater sits in the foot loop.
• Cold bathroom air and a poorly insulated room, which the heater has to work against.

What to Check, in Order

1. Fill hot from the faucet. The heater cannot raise a cool fill. If the fill itself is not hot enough, the hot water heater requirements guide covers what the house supply needs to deliver.
2. Run the hydro massage. The heater has no switch of its own and comes on only with the hydro pump. With the hydro off, the water cools like any bath.
3. Confirm the package. The in line heater comes with every hydro package and is not on soaking or air only tubs; it cannot be added to those configurations.
4. On a Hydro plus Hydro Foot tub, run the foot massage. The heater is powered with the foot pump on those builds, so the seat jets alone will not warm the water.
5. Check the heater cord at the control box. A heater plugged into the wrong port never runs. The cords and connections guide shows which port is which. If the heater and lights stopped working together, also check the green LED on the box and the GFCI.

When to Open a Ticket

If you fill hot, the hydro runs, the cords are on the right ports and the water still drops noticeably during a hydro session, open a ticket at ellasbubbles.com/support or call your Ella dealer or the team at (800) 480-6850. Include your serial number, your therapy package, and a photo of the control box with every cord visible so the team can confirm the heater connection.

As the video explains, you set the fill temperature with the faucet, and when the hydro massage runs the in line heater works with the pump to maintain a consistent warm temperature for the length of the soak.

Common Questions