This type of problem is typically caused by low water flow. Noritz tankless water heaters have a minimum flow requirement (0.5 gpm for most models.) If this flow requirement is not met, the heater will not fire.
If you heater shuts off during usage, here are a few things to check:
- Ensure your filter is clean and free of debris (instructions)
- Verify gas, water, and power are supplied to the heater
- Try lowering your water temperature to 120°F. This will ensure you are using more hot water and meeting the minimum flow rate requirement
If you are still having problems, please contact a local Noritz Service Agent, listed at http://support.noritz.com/servicereplocator.php, or Noritz Technical Support at 1-866-766-7489
Gallons per minute
measure of fluid volume (e.g. water, gas) per unit time