Manual I'm getting a C2 11 error code and a C8 12 error code. What are they and can I fix them?

Here is a link to all the Noritz error codes. There is NO Code 67. https://inspectapedia.com/heat/Noritz-NCC199-Error-Codes.pdf

Tankless require yearly service to keep burner and combustion parts clean and check electrical connections, gas solenoid, gas pressure, venting, etc.
Read product manual for advisories and recommended maintenance.
Yes, aren't you glad you saved the manual.
Always check that local area has affordable and qualified service technician for your brand before buying tankless.
Before calling service technician, copy following link for general troubleshoot resources, including some manuals, and links to Bosch.
http://waterheatertimer.org/pdf/No-Error-Code.pdf
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

Try turning temperature down.
The fact there is no error code, and the gas is not firing correctly, means you have a small unit with no error codes and PC board has failed ... or it means you have a unit with error codes and possibly bad PC board.
If problem is the PC board, then Bosch will send you new board, and expect same level of repair success as though your computer's motherboard was replaced.

You can buy ordinary box-store tank-type heater and install yourself same day for about $325.
Then maintain and fix it yourself. I recommend AO Smith/American/State/Reliance/Kenmore/Whirlpool since these are easy to maintain with clear directions in manual, plus AO Smith posts service manuals for the whole line of products, and any local plumber can fix them with ez-to-locate generic parts.
http://waterheatertimer.org/How-to-install-gas-water-heater.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Why is it always Rheem problems?
Every water heater problem at fixya is Rheem.
And Rheem doesn't post any service manuals, like the other two big manufacturers, AO Smith-American, and Bradford White.

Rheem 2012 manual says if error 13 still displays, then contact installer or service technician. Mo Money buddy.
This is about oxygen sensor, poor combustion, bad venting, inadequate air supply, failed sensors, etc.
Get more fresh air to unit and see if that solves problem. The call service technician, and get out wallet.
Copy following link for Rheem-richmond tankless troubleshoot.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Maintain water heater according to instructions in manual to avoid common error codes. Of course this means you have to service the unit each month, and each year, without guarantee the thing will work correctly.


If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

The year 2009 Bosch 24ES manual does not show error code 14.
Your manual may be different.
Call Bosch 1-800-642-3111
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html
http://waterheatertimer.org/pdf/Bosch-GWH2400ES.pdf

Don't forget to read the product manual for required yearly maintenance, and performing this maintenance will eliminate many common error codes.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Before calling service technician, open following link for resources including error codes, Rheem chat and possible manual:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Error codes are considered start-point for troubleshooting, and give service technician direction for isolating problem.
Error 82 appears as 'gas type data failure' > 'Program PC board for proper gas type.'

Gas type is choice between LP gas and NG natural gas.
Gas type programming is controlled with dip switch setting.
I do not have service manual for product, and would not suggest changing dip switches without specific information beforehand.

Yes. Contact Bosch.
Error codes are considered start-point for troubleshoot.
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

Tankless are complex electronic machines.
If on-site plumbers cannot figure out problem, then you need trained service technician with a service manual for your specific product, who can ohm-test the electronics.
Bosch will have a list of trained service technicians. And maybe Bosch has another step for fixing problem yourself.

Fix most tankless problems yourself, same day, for $330.
http://waterheatertimer.org/How-to-install-gas-water-heater.html

Before calling service technician, open following links for troubleshooting resources including Rheem phone, chat, error codes, general maintenance pdf, and generic service manual:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html
http://waterheatertimer.org/pdf/Tankless-maintenance.pdf
http://waterheatertimer.org/pdf/Tankless-service-manual.pdf

Error codes are considered start point for troubleshooting.
Error 11 is 'no ignition' or 'no gas'
You have checked gas and pressure, and had parts cleaned.
Other causes can include: igniter wiring, bad igniter, loose wire on gas solenoid, bad solenoid, improper grounding.

Before calling service technician, open following links for common error codes, Rheem chat, and possible manual.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html
http://waterheatertimer.org/pdf/ErrorcodeTroubleshooting.pdf
http://waterheatertimer.org/pdf/Tankless-maintenance.pdf

Error codes are start point for troubleshoot.
C2 11 is 'no ignition' or 'gas shut off vale is not open'
Gas shut off valve handle must sit parallel with gas line.
This kind of error code can be air in gas line, improper grounding at electrical outlet, bad igniter, shorted solenoid, loose connections, etc.
Most tankless manuals recommend yearly service, and that type of work usually covers cause for most common error codes: for example checking gas pressure, gas line, air in gas line, clean and check burner and combustion parts and igniter, inspect that vent condensate is properly draining and vent has good draft, clean water filter, clean air intake, check for loose wires, delime heat exchanger, test outlet with circuit analyzer etc.

Before calling service technician, open following link for error codes, Rheem chat, and possible manual:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html
http://waterheatertimer.org/pdf/ErrorcodeTroubleshooting.pdf

Error codes are considered start-point for troubleshooting.
Error 11 is 'no ignition'
Without ignition, the burner will not turn on and heat water.

This problem can be caused by low gas pressure, air in gas line, defective tankless parts such as gas solenoid, loose electrical connections, improper electrical grounding, bad igniter, etc.
Problem can also be caused by combination of problems.
Good news is that error code shows 1 code and not multiple error codes that can indicate larger failure including PC board.

Each tankless instruction manual recommends yearly maintenance where technician will clean burner parts, bleed gas line, check gas pressure, check air and venting, etc.
Yearly service covers the cause for most common error codes.

e2 is not shown among common error codes:
Error e2 might be: Brownout condition or too low of voltage to thermostat. Double check wiring and check for 24 vac between R and C. E2 will clear 15 sec after proper voltage is restored.

Before calling service technician, open following link for Rheem troubleshoot resources including Rheem chat and typical generic manuals and common error codes:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Model number and serial number are required for Rheem contact, and then they tell you what error code means without saying how to fix it, and then tell you to call service technician.

Tankless water heater manuals each say to have qualified technician perform yearly service. Most causes for common error codes are covered by yearly service.

Yearly service is fairly standard in the HVAC and water heater industry with advancement of high-tech 'energy' saving appliances. Of course all costs are energy, and the service call probably costs more that the 'energy' saved by energy-saving appliance. But with high tech stuff like tankless, it is good to have a reliable service guy who knows your machine.
http://waterheatertimer.org/images/Tankless-wiring-1200.jpg