How to Troubleshoot a Bosch Tankless Hot Water Heater

Tankless water heaters produce hot water "on demand" for showers, baths and sinks.

Bosch, a manufacturer of home appliances, says its tankless hot water heaters have an average life expectancy of more than 20 years and can save a household up to 50 percent on post-installation energy costs. According to the company's Bosch Hot Water.com website, its tankless hot water heaters provide unlimited hot water to appliances and devices throughout a home, but issues can arise. Troubleshooting the problem can help you resolv an issue prior to calling--and paying--a service technician.

Things You'll Need

• Power supply
• Screwdriver
• Towel

Instructions

1. Ensure the Bosch hot water heater is connected to a power supply, if the display is blank on the hot water heater. Turn the power button to "On" and restart circuit breakers or fuses, if necessary.

2. Look at the right side of the heater and ensure the cold water inlet connection is connected firmly to the water heater if the burner does not ignite when the water heater is turned on. Look at the water path, including showerheads, nozzles and other water inlets, to ensure they are free of obstructions. Clean if needed.

3. Clean the inlet filter screen if the water dispensed from the water heater is not hot enough. The inlet filter screen is located inside the cold water inlet fitting, found on the right side of the hot water heater. Close the cold-water shut-off valve and loosen the screw on the inlet fitting. This causes water to drain, which is normal. Lift out the round filter and rinse well with water. Dry thoroughly and replace the filter inside the inlet. Tighten the screw on the inlet fitting and open the cold-water valve.

4. Reduce the number of appliances and devices that require hot water simultaneously if the water flow or pressure seems low. Lower the temperature on the thermostat slightly, as this increases the water flow rate.

5. Lower the temperature setting on the thermostat if the hot water dispensed varies in temperature or is too hot. Alternatively, increase the thermostat temperature if the water temperature seems too cold.

6. Check seals and valves and tighten if the water heater seems excessively noisy during operation. Ensure that the vents are not blocked.

Tips & Warnings

• Unplug and turn off the water heater before performing any maintenance to the unit.

References

• Bosh Hot Water: Tankless Water Heaters
• Bosch Hot Water: Tankless Water Heater Instruction Manual