Tankless Water Heater Systems

Tankless Water Heaters and Water Quality

Up until recent times, the primary choice for consumers have been the standard tank style water heaters. There is no argument that compared to tankless water heaters, standard tank style heaters are much less efficient in the heating of water. There is one advantage tank style water heaters have over the relatively new tankless technology, that is their ability to continue providing hot water in high water hardness conditions. Even with a considerable amount of mineral scale deposits, traditional tank style heaters will continue to heat water until the desired temperature is reached, despite the fact that the process is even more wasteful of energy when mineral deposits are present.

Tankless water heaters provide instantaneous heating of water and even moderate scale build up on heat transfer surfaces greatly diminish their efficiency thus requiring frequent deliming service in hard water applications. This is most evident in applications where a tank style system is replaced by a tankless water heater in hard water areas. Prior to replacing the tank style water heater, the owner may have never had to replace elements or maintain the heater for problems caused by hard water mineral deposits.

Their tank style heater continued to work inefficiently, but still provided hot water. Once they replaced the tank style heater with a tankless heater, they found much to their surprise the need for periodic deliming. Tankless water heaters are much superior to tank style heaters in all aspects except water quality forgiveness. Water softening has often been recommended as pretreatment for tankless heaters.  This is a costly solution that takes up valuable space and adds another requirement of having to maintain the unit with salt.

SFES Tankless Water Treatment Systems utilize HydroBlend™, effectively controlling mineral scale deposits on heat exchangers in tankless water heaters. HydroBlend™ is specifically formulated to work in high-temperature / high-hardness environments providing unparalleled mineral scale prevention and corrosion control.

Note:  The PF-10 SS Series units must be installed on a cold water inlet to the tankless heater.  If there is a recirculation line feeding hot water to the inlet connections, use the HBW Series units (warewash applications) if the water line is hot.  The standard PF-10 SS Series units may be installed if there is a recirculating loop as long as it is installed outside the loop on the cold water inlet water line.

SFES Tankless Water Treatment Systems utilize a high pressure clear filter housing that is rated 125 psi for placement on the cold water line feeding the tankless water heater.  This allows a simple glance at the housing to determine when the ScaleStickcartridge is depleted.

SFES Tankless Water Treatment Systems are offered in three cartridge sizes allowing for application on single or multiple units depending on water flow rates and usage characteristics.


For use on a single tankless heater with an average continuous flow rate of 1-3 gpm.

Note:  The average continuous flow is an estimate of the average flow the tankless unit will be heating.  Maximum flow rates through the treatment system are approximately 12 gpm depending on incoming water pressure.  This applies to all of the treatment systems for tankless heaters.


For use on a single or twin tankless heater(s) with an average continuous flow rate of 2-4 gpm.


For use on a single or twin tankless heater(s) with an average continuous flow rate of 3-6 gpm.