Water Is Too Hot; Water Is Not Hot Enough - Bosch Pro Tankless GWH-425-HNO-N Instructions For Use Manual

B 4. Check the inlet water pressure. For installation on
a private well system with the use of a pressure tank,
the lowest pressure range setting recommended is
30-50 psi (2.07 - 3.45 bar). Confirm that the
pressure tank is not water logged.
B 5. Service water valve See chapter 5.1 for intervals
and instructions.
B 6. ECO (overheat sensor) tripped due to overheating
re-ignite the appliance 10 minutes later. If it happens
again, contact your service person.
6.5

Water is too hot

B 1. Check gas type on right side panel rating plate.
NG is a natural gas unit and LP is for liquid propane.
B 2. Since the unit does not measure incoming water
temperature, the output water may be warmer in the
summer than in the winter. Use the slide control to
lower output temperature as outlined in chapter 4.4.
B 3. Contact you service person if water temperature
does not lower per
chapter 4.4.
6.6

Water is not hot enough

B 1. Adjust the temperature per chapter 4.4.
B 2. Shut off installer supplied cold water supply valve
(if none installed, install before proceeding). Open all
hot water taps supplied by the 425 HNO. Wait 5
minutes and check all taps. Water running is a sign
of a plumbing cross-over. Consult a local plumber or
service person for help in correcting plumbing cross-
over.
B 3. While the heater is running with full hot water flow,
the flames should be 3-4" tall off the burner bed. If
the flames are not this tall, have the gas pressure
measured per chapter 3.6 by a licensed gas
technician or your service person.
B 4. Service water valve See chapter 5.1 for intervals
and instructions.
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procedure outlined in
Troubleshooting
19