This heater pad has easy, peel-and-stick installation onto the bottom of your tank or step. The flexible carbon fiber material is designed to fit the contours of any surface. The pad is meant for use on fresh water tanks, but can be installed onto gray water or black water tanks. Please note, however, that adding a heat source to a gray water or black water tank may create excess gasses and odors.

The pad has a white wire for ground, and a red wire for power. This 2-wire design is compatible with DC power while your RV is in transit. It can also run through a converter while connected to a power source when your RV is parked.

Additionally, you are able to install this pad with other ThermaHeat heater pads (sold separately). In order to do this, they must be connected and run parallel. You would daisy-chain the red wires together and connect them to the battery of your RV or camper and then daisy-chain the white wires together and ground them. In order to turn the pads on and off, you will need to install a switch (sold separately) between the battery and the pads.

Full-contact, weatherproof heating pad helps prevent your RV holding tank or step from freezing. Built-in thermostat automatically turns the heating pad on and off depending on the temperature of the tank or step. Easy, peel-and-stick installation.


  • Full-contact heater pad keeps your exposed RV holding tank or step warm during freezing temperatures
    • Works with tanks with a 29 to 40 gallon capacity
    • Can also thaw out a tank system or a step if it's already frozen
  • Built-in thermostat automatically operates the heater pad
    • Turns on when the tank or step temperature reaches 45 degrees F
    • Turns off when the tank or step temperature reaches 67 degrees F
  • Flexible, weatherproof carbon fiber material bends to fit the contours of a surface
  • Easy, peel-and-stick installation onto the bottom of your tank or step
  • 2-Wire design with 16-gauge wires
    • White wire is for ground
    • Red wire is for power
  • Compatible with DC power when in transit
    • Runs through a converter while connected to a power source when your RV is parked
  • Cold room tested down to -32 degrees F
  • QAI certified


  • Pad dimensions: 25" long x 7-1/4" wide
  • Pad thickness: 3 mm
  • Length of wires: 36"
  • Input voltage: 13.5V DC
  • Power draw: 5.8 amps
  • Wattage: 78 watts
  • 1-Year warranty
  • Note: This heater pad should be installed on non-conductive surfaces only.

The Therma Heat RV tank and step heating pad meets the following certification standards:

  • Safety for Electric Heating Appliances, UL499
  • Safety for Heating Elements (CSA) C22.2 No. 72-m1984 (R2004)
  • Flammability tests (UL) 746C, 15 and CSA 0.17,9,2
  • Dieletric Voltage Withstand Test (UL) - 1000 volts/1 minute
  • Thermal Aging Test (UL)

Note: This heater pad should be installed on non-conductive surfaces only.

ThermaHeat Water Heater Pad Holding Tank or Steps -- SL-ST725G


Allowing water to freeze in the system may result in damage to the pump and plumbing system.

Non-Toxic antifreeze for potable water may be used with Flojet pumps.

Follow manufacturer's recommendations.

Refer to coach or equipment manufacturer's instructions for their specific winterizing and drainage procedures.

Do not use automotive antifreeze to winterize potable water systems. These solutions are highly toxic and may cause serious injury or death if ingested.

1. Drain the water tank. Open tank drain valve and plumbing drain valves if applicable. You may use the pump to drain the tank by opening all the faucets in the system. Allow the pump to operate until the tank is empty. Do not operate the pump more than 15 minutes continuously.

2. Open all faucets and flush the toilet to purge all the water from the pump and the plumbing system. Run the pump until no water is coming through the faucets. Turn power to the pump off. Be sure that all the water from the drain lines are drained.

3. Remove quick connect inlet and outlet fittings from the pump and turn the pump on to pump out remaining water from the pump head. Be sure to have a catch pan or a rag under the pump to prevent water from spilling onto the RV. Turn the pump off once the plumbing is empty. Leave the fittings disconnected from the pump until the system is ready to be used again. Make a note on your tank filler that the plumbing is not connected.

4. Be sure that all faucets are left open to protect against damage to the plumbing. Portable water systems require periodic maintenance to deliver a consistent flow of fresh water. Depending on use and the environment the system is subject to, sanitizing is recommended prior to storing and before using the water system after a period of storage. Systems with new components, or ones that have been subjected to contamination, should also be disinfected as follows: NOTE: The sanitizing procedure is in conformance with the approved procedures of RVIA ANSI A119.2 and the US Public Health Service.

1. Use of the following methods to determine the amount of common household bleach needed to sanitize the tank.

1. A) Multiply “gallons of tank capacity” by 0.13; the result is the ounces of bleach needed to sanitize the tank.

1. B) Multiply “Liters of tank capacity” by 1.0; the result is the milliliters of bleach needed to sanitize the tank.

2. Mix into solution the proper amount of bleach within a container of water

3. Pour the solution (water/bleach) into the tank and fill the tank with potable water.

4. Open ALL faucets (hot and cold) allowing the water to run until the distinct odor of chlorine is detected.

5. The standard solution must have four (4) hours of contact time to disinfect completely. Doubling the solution concentration allows for contact time of one (1) hour.

6. When the contact time is completed, drain the tank. Refill with potable water and purge the plumbing of all sanitizing solution.