The Safe-T-Cover Blog

Selecting the Right Heater for a Backflow Cover

Posted by Craig Carmon on January 27, 2021

When selecting a backflow cover for your reduced pressure zone backflow assembly (RPZ) it’s easy to overlook freeze protection. But if you don’t take the proper steps to insulate and heat your enclosure, you could end up with a frozen backflow preventer and huge problems. Heaters for backflow covers can maintain freeze protection in the harshest environments, depending on where it’s placed.

More than half of the United States and all of Canada will average a temperature of 32 degrees or lower during its coldest month. More than a day at these temperatures can lead to freezing if the backflow cover does not have heat. In fact, according to the National Weather Service, some states will see the temperature drop below freezing as early as August.

That’s why it’s critical to install the backflow cover heater in the optimal location. Let’s look at the three types of heaters to consider and the best place to install them.

Types of Backflow Cover Heaters

When selecting the backflow cover, it is important to consider the type of heater needed. The three types of heaters available are:

  1. Self-Regulating Heat Cable
  2. Wall-Mounted Heater
  3. Slab-Mounted Heater

Each has unique characteristics, but keep in mind that all heaters are not created equal. Here’s a closer look at each option:

Self-Regulating Heat Cable

Self-regulating heat cables automatically adjust their power output to compensate for temperature changes. When the ambient temperature drops, the cable’s power increases, and more heat is produced. Conversely, when the ambient temperature goes up, the cable’s power output goes down and it produces less heat.

The self-regulating heat cable is wrapped around the backflow device and plugged into a power outlet. Most enclosure manufacturers offer the heat cable option for small-diameter pipes, typically 2” diameter and smaller.

Wall-Mounted Heaters

For backflow preventers larger than 2 inches in diameter, a heat cable may not be the best option for the backflow cover. A wall-mounted heater is the next option. In fact, most heaters in the industry are wall-mounted, but that doesn’t necessarily make it the most cost-effective or safest option.

Safe-T-Cover's King Heater is a wall-mounted-heater, featuring a built-in thermostat and meets ASSE 1060 Class 1 for use as freeze protection. But most wall-mounted-heaters are noncompliant with the ASSE standard because they are not UL wet/damp certified and simply are unable to deliver the most effective amount of freeze protection to keep your backflow preventer safe. 


Wall heaters must be mounted to one side of the backflow cover due to doors and access panels. And because most wall heaters are not wet/damp certified, they must be mounted at least 12 inches off the slab, which creates another concern.

Heated air rises, so the warmth channels of the wall-mounted heater are heading straight to the top of the backflow cover long before uniform warmth is achieved. The objective of the heater is to keep the backflow preventer warm, not the top of the enclosure. No one wants the backflow preventer to freeze. This is an expensive repair and the building could be without water while the repair is being made.

So just what is the best solution for heating the backflow cover? The slab mounted heater.

Slab-Mounted Heaters

A slab-mounted heater is the best option. It will provide the peace of mind you’re looking for because of its many features, including:

  • Meets all ASSE 1060 requirements
  • Provides heat to the equipment inside your aluminum enclosure as well as the riser pipes beneath the slab
  • Will maintain an interior temperature of 40 degrees — even with an outside temperature as low as negative 30 degrees. 

Enclosure Heater

Safe-T-Cover’s patented slab mounted heaters are also certified for wet/damp conditions, which is necessary as an RPZ may dump water through the relief valve.

Slab-Mounted Best For Backflow Covers

The HCH Series Floor Heater bolts directly to the slab, producing radiant heat that penetrates 16 inches down into the vertical pipes. The system is also designed to withstand water spray conditions inside the backflow cover and meets the requirements of the UL-2021 section 49 rain test. Safe-T-Cover also doubles the roof insulation to R-18, which reduces the energy consumption of the heater.

As a design engineer, specify an ASSE 1060 class 1 backflow cover. You’ll rest easy knowing the owner will never call and ask why the backflow device is frozen. Mother Nature surprises us all of the time — even Florida and Nevada can freeze sometimes.

If you’d like more information on the type of backflow cover and heater you need on your next project, contact us and we’ll be glad to help.

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Topics: Enclosure Materials