6 720 608 036
22
Troubleshooting
5. If water is still too hot, consult service bulletins on
www.boschpro.com
to lower outlet temperatures
further.
6. If the water has a high mineral content, the heat
exchanger may be scaled internally. This restricts the
water path, causing the water to boil and produce
extremely hot temperatures. To descale the heat
exchanger, consult service bulletins on
www.boschpro.com.
6.8 Water is not hot enough
1. Verify gas type indicated in the rating sticker located
on the cover's right hand side, coincides with the gas
type you are using. NG is a natural gas unit and LP is for
liquid propane (see chapter 2.2).
2. Flow at one particular tap is too great or too many
fixtures are running at one time. Lower flow to stay
within heater's specifications.
3. Ensure the power adjustment knob is all the way
clockwise for highest temperatures. In addition, the
temperature adjustment knob maybe set too low. Raise
the setting and test the water temperature. This dial
turns counterclockwise for lower temperatures and
clockwise for higher temperatures.
4. Close installer supplied cold water shut off valve (if
none installed, install before proceeding). Open all hot
water taps supplied by the heater. Wait 5 minutes and
check all taps. Any water running is a sign of a plumbing
crossover. Consult local plumber or service person for
help correcting a plumbing crossover.
5. Inspect the water path outside the heater for
obstructions. Make sure all outlets (i.e. showerheads,
faucet aerators and whole house filters) are clear of
debris. Also, the water heater's inlet filter should be
inspected and cleaned. See chapter 5.2.
6. The water valve assembly, which allows gas flow to
the burners, requires periodic maintenance (every 2-5
years depending on water quality and use). Visit
www.boschpro.com to purchase water valve rebuild kit
to service the water valve.
7. Gas pressure is too low. Ensure gas pressure is in
accordance with specifications in the installation
manual. See chapter 3.9. A gas pressure reading is
needed to proceed further. Contact your original
installer or a local certified gas technician to obtain this
reading.
6.9 Burners ignite without water flow
1. The water valve may be dirty and sticking, prohibiting
it from fully closing the gas valve. This part requires
periodic maintenance (every 2-5 years depending on
water quality and use). Visit www.boschpro.com to
purchase water valve rebuild kit to service the water
valve.
6.10 Low hot water pressure
1. Confirm adequate flow rate through the unit. With
cold supply shut off to the unit, disconnect hot outlet
side to the unit. Place a gallon jug under hot water
outlet to catch water. Open cold water supply and
measure flow rate out of the unit. With temperature
adjustment knob set all the way clockwise, the flow rate
should be close to 2GPM (filling the jug in 30 seconds
or less). If the flow rate is not adequate, inspect and
clean inlet filter screen. See chapter 5.2.
2. Confirm the incoming water pressure to the unit is
above the required 30psi.
3. Inspect the water path outside the heater for
obstructions. Make sure all outlets (i.e. showerheads,
faucet aerators and whole house filters) are clear of
debris.
4. Be sure to run only one major fixture at a time with this
water heater. Opening too many taps at one time can
disperse water flow resulting in diminished flow/
pressure at all outlets.
5. If the water has a high mineral content, the heat
exchanger may be scaled internally. This restricts the
water path, causing diminished water flow. To descale
the heat exchanger, consult service bulletins at
www.boschpro.com.
6.11 Noise when heater is running
1. Confirm adequate flow rate through the unit. With
cold supply shut off to the unit, disconnect hot outlet
side to the unit. Place a gallon jug under hot water outlet
to catch water. Open cold water supply and measure
flow rate out of the unit. With temperature adjustment
knob set all the way clockwise, the flow rate should be
close to 2 GPM (filling the jug in 30 seconds or less). If
the flow rate is not adequate, inspect and clean inlet
filter screen. See chapter 5.2.
2. Inspect the water path for obstructions. Make sure all
outlets (i.e. showerheads, faucet aerators and whole
house filters) are clear of debris. Restrictions in the
water path can slow water flow through the heat
exchanger causing it to boil and make noise.
3. If the water has a high mineral content, the heat
exchanger may be scaled internally. This restricts the
water path, causing the water to boil resulting in noise
and overheating. To descale the heat exchanger,
consult service bulletins on www.boschpro.com.
6.12 Burners do not burn cleanly, yellow
flames when operating
1. Verify gas type indicated in the rating sticker located
on the heater's right hand side, coincides with the gas
type you are using. NG is a natural gas unit and LP is
for liquid propane (see chapter 2.2).
2. Gas pressure may be inadequate resulting in
improper combustion. Ensure gas pressure is in
To Next Page
Loading...
