Water Treatment
If this water heater will be installed in an application where the supply water is hard, the water must be
treated with a water softener or scale inhibitor. Refer to the below tables for suggested treatment and
maintenance measures to be taken based on the water hardness level. Damage to the water heater
as a result of water in excess of 12 gpg (200 mg/L) of hardness is not covered by the Electrolux Home
Products, Inc. Warranty.
for code, sizing, and installation guidelines; the below diagram is for reference only.
Residential Use Treatment Guidelines
Hardness
Type of Water
Level
0-1 gpg
Soft
(0-17 mg/L)
1-3 gpg
Slightly Hard
(17-51 mg/L)
3-7 gpg
Moderately
Hard
(51-120 mg/L)
7-10 gpg
Hard
(120-171 mg/L)
10-14 gpg
Very Hard
(171-239 mg/L)
Extremely
> 14 gpg
Hard
(> 239 mg/L)
* Install Isolation Valves to allow for ushing.
** Flushing is required if a water treatment device is not installed.
Electrolux
Condensing
Tankless Gas
Water Heater
Pressure
Relief
Valve
Drain
26
Treatment
Flush
Device
Frequency*
None
None
None
None
Water Softener
Once a Year**
Scale Inhibitor
Water Softener
Once a Year**
Scale Inhibitor
Water Softener
Treatment
Required
Scale Inhibitor
Treatment
Water Softener
Required
Scale Inhibitor
Water Treatment System
Cold to Water
Heater
Shutoff Valve
Hot Water to Fixtures
Commercial Use Treatment Guidelines
Hardness
Type of Water
Level
0-1 gpg
Soft
(0-17 mg/L)
1-3 gpg
Slightly Hard
(17-51 mg/L)
3-7 gpg
Moderately
Hard
(51-120 mg/L)
7-10 gpg
Hard
(120-171 mg/L)
10-14 gpg
Very Hard
(171-239 mg/L)
> 14 gpg
Extremely
(> 239 mg/L)
Hard
* Install Isolation Valves to allow for ushing.
** Flushing is required if a water treatment device is not installed.
Shutoff Valve
Optional Sediment
Filter
Water Treatment Device
Treatment
Flush
Device
Frequency*
None
None
None
None
Water Softener
Once a Year
Scale Inhibitor
Water Softener
Twice a Year
Scale Inhibitor
Water Softener
Treatment
Required
Scale Inhibitor
Water Softener
Treatment
Scale Inhibitor
Required
City Water Supply
**
**