Heaters

In any area where temperatures can fall and stay below 32°F for more than 24 hours, our recommendation is to add an enclosure heater. This seems to be one of those 'pay me now or pay me later' decisions we all deal with. As a design engineer, insisting on an ASSE 1060 Class I conforming enclosure allows me to rest easy knowing the owner will never call and ask why their backflow device is frozen and who will be paying an expensive backflow replacement bill, not to mention recouping losses due to a building being without water until the repair is made.

We routinely sell enclosure heaters for projects in the Sun Belt states: Texas, Louisiana, Mississippi, Alabama, Georgia and Florida. Mother Nature has surprised us in recent years: even Florida and Nevada can have very low temperatures, causing backflow preventers to freeze and fail. This post about backflow cages goes into more detail explaining why they're not a sufficient option for total protection.

Wall Heaters

Most backflow cover heaters in the industry are wall- or panel-mounted. This method is simply unable to deliver equivalent freeze protection provided by a floor- or slab-mounted heater. Because of the door configuration, wall-mounted heaters must be mounted to one side and may use an aluminum mounting plate. And because they do not meet wet/damp requirements, they must be mounted at a minimum of 12” off the slab. Remember that warm air always rises, so these heaters' warmth channels straight out of the top of the enclosure long before uniform warmth is achieved, if at all.

Slab Mounted Heaters

On the other hand, a slab-mounted enclosure heater provides heat to both the backflow equipment and up to 16 inches beneath the slab for the riser pipes. These heaters will maintain a standard interior temperature of 40°F with an outside temperatures as low as –30°F as is needed to meet ASSE 1060 Class I requirements. Safe-T-Cover's patented slab-mounted heaters are certified for wet/damp conditions, obviously necessary for waterworks equipment in outdoor conditions. Their rugged and compact design has proven reliable for backflow preventer protection in frigid low temperatures for years.  

Heat Wrap Cable

We also offer a self-regulating heat cable. This enclosure heat option is wrapped around the backflow device. Most enclosure manufacturers, including Safe-T-Cover, only provide a heat cable option for pipe diameters two inches or less in small enclosures.

This video from Instrument Specialties is a good overview of how these cables work.

Safe-T-Cover offers 1000 and 2000 watt slab-mounted box heaters at 120V and 240V heating power. You should set the thermostat for wall- and slab-mounted heaters at 40ºF and the heater will maintain this temperature all the way down to –30ºF. Safe-T-Cover has sold enclosure heaters for many years in Canada and in upstate New York, where winter temperatures can remain below freezing for extended periods of time. For more information, you can read our case study from St. John's, Newfoundland about how well enclosure heaters perform in harsh environments.

Be Prepared is the Boy Scout motto, and Safe-T-Cover also advocates being in that state of readiness. The first and foremost way to prepare against freezing pipes is to know the power has failed at the enclosure. We offer three different power and temperature failure alarms. There are basic models with a light and alarm, and systems with remote monitoring and cell phone alerts. 

The second way you can be prepared is by having a contingency plan to provide some type of box heating for the enclosure if it appears the power might be out for an extended period and the temperatures will remain below 32ºF. A 9,000 BTU portable propane heater will more than replace the output of an electric heater.

For wall-mounted and slab-mounted enclosure heaters, a thermostat determines when the heater will activate. Most wall-mounted heater thermostats are built into the heater body and located high enough on the wall for the heater to be safe from water damage. For a slab-mounted enclosure heater, the thermostat is installed about 12” above the slab. The thermostat is set at 40ºF and designed to maintain this temperature inside the enclosure all the way down to –30ºF. That is, if the box heater satisfies ASSE 1060 Class I requirements.