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Unit flashes the number 20
A 20 error code means the high limit switch is being tripped. This is most typically caused when scale develops in the heat exchanger. I'd recommend performing a descale on the heater to resolve the problem. Make sure to follow the instructions that came with your isolator valve kit.
on Jul 12, 2010
My noritz water heater: error code: 11. It is an N-0931m. Thanks
Code 11 is ignition failure.
Ensure that your gas is turned on.
Start by checking the vent system to ensure there is no obstruction or separation in the vent system.
Second I would recommend flushing the water heater with vinegar or Rectorseal Calci-Free. Calcium and scale build up in tankless water heaters can cause several failures that are not directly related to the specific code displayed on the heater.
If the problem persist I would look for a plumber that is familiar with tankless water heaters.
on Mar 02, 2019
NORITZ CB BOILER BURNER NOISE
You should try to describe the noise and what is happening when the noise occurs. Then someone may be able to give you some diagnosis of the problem. For example, does it make a big boom sound went it lights the burners? Then you might need to clean and adjust the pilot light.
on Dec 25, 2018
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