Water quality can have an impact on appliance longevity. Water
supplied to the Greentherm T9800 SEO must be in accordance
with table 8 and fig. 12.
For water analysis data call your local water department, or if on
a well, have well water analyzed periodically. Heavy scale will
form if the combination of water total hardness and pH exceeds
the values specified in fig. 12 (grey area), Bosch recommends
consulting a local water treatment professional for water
TDS (total Dissolved Solids) mg/l or ppm 690
Water total hardness and pH values
Greentherm T9800 SEO 160/199 | SECO 199 – 6 720 817 281 (2018/12)
6.5 - 8.5
mg/l or ppm 200
mg/l or ppm 2.0
mg/l or ppm 250
mg/l or ppm 1.0
mg/l or ppm 0.3
mg/l or ppm 0.05
mg/l or ppm 5.0
1. Total Harness and pH maximum values must be evaluated in
combination. Indicated maximum values will be reduced
according to fig. 12.
2. Combined values of total hardness and pH must be under
the indicated grey area. (e.g. the pair [180;8.3] [total
hardness; pH] is not acceptable).
▶ This heater is not approved for preheated water
applications exceeding 140 °F (60 °C) for Residential
appliances, in these cases use a 3-way valve or mixing valve
must be installed before the appliance to prevent water
exceeding 140 °F (60 °C) for Residential appliances, from
entering the appliance.
▶ When facing the heater, the ¾" cold connection is on the
bottom right and the hot connection is on the bottom left.
▶ Tighten all water connections with the support of a wrench,
see Fig. 13.
 Hot connection
 Cold connection