Bosch 830ES Technical Service Bulletin page 2

2 | Resetting the Watervalve
7. On the motor side, slowly rotate the gear clockwise to "0" (Fig. 3). There are
gears inside this motor that cause resistance, do not try to move it fast or
you will damage the gearing.
Figure 3
8. Once that is completed, make sure you can blow through the valve freely
from the bottom where the cross diverter is (Fig. 4). When you forcefully
blow through the valve, you should hear the impeller spinning. If not, use
a small pick or similar device to manually move it. It should move freely
with no resistance. Any resistance could be signs of buildup inside the
valve. Flushing out the valve at this point would be your only way to clear
that obstruction. The impeller is not removable on these valves. If it can't
spin freely by fl ushing out the valve or manually rotating it, you may need to
replace the valve.
Figure 4
9. After performing the service, attach the watervalve engine to the watervalve
body with the 2 phillips head screws as shown in Fig. 1.
10. Plug the wiring back in, and reinstall the clips on both the incoming and
outgoing side of the valve.
11. Slowly turn on water supply to check for leaks, before powering up and
returning the tankless unit to service
Data subject to change without notice | Printed in the USA | BTC 740002333 A | 05.2018
Technical Service Bulletin
Bosch Thermotechnology Corp.
65 Grove Street
Watertown, MA 02472
Tel: 1-866-642-3198
Fax: 1-954-776-5529
www.boschheatingandcooling.com
Bosch Thermotechnology Corp.