Rheem over heat limiter

Question edited for clarity. Looks like you encountered autocorrect

The manual is here. It doesn't mention a reset button.

Rheem RETEX-27 instruction manual and user guide

https://mans.io > Rheem > Tankless Electric Water Heaters

Rheem RETEX-27 Performance 27 kw Self-Modulating 5.27 GPM Tankless Electric Water Heater download pdf instruction manual and user guide.

But this says it does, or may have?

Where Is the Reset Button on a Rheem Hot Water Heater? On Rheem water heaters, the reset button is usually a red button located near the thermostat, at the middle of the limit switch. To access it, you will need to remove the metal panel on the unit. The red button is behind the insulation.

How to Reset Rheem Tankless Water Heater - Quick Fix

'OHL = Ontario Hockey League'? I know it well. :>)

Sure, swap it over, or just leave it as is.

This is the latest I have. recommend calling Rheem customer service. They are very good
14 Overheat Wrap Fault
Ensure high fire and low fire manifold pressure are correct.
Check gas type of unit and ensure it matches gas type being used.
Check heat exchanger for cracks and/or separations.
Ohm out safety circuit.
Check for improper conversion of product.
Check for restrictions in air flow around unit and vent terminal.
Check for a foreign materials in combustion chamber and/or exhaust piping.

Code 14 Overheat Wrap Fault
Ensure high fire and low fire manifold pressure are correct.
Check gas type of unit and ensure it matches gas type being used.
Check heat exchanger for cracks and/or separations.
Ohm out safety circuit.
Check for improper conversion of product.
Check for restrictions in air flow around unit and vent terminal.
Check for a foreign materials in combustion chamber and/or exhaust piping.

Replace heating elements can be found at amazon, click here and take a look: Amazon com rheem heating element . I hope this was helpful... cheers

It could be element shorted to ground through steel tank, so don't touch tank when breaker is ON.
Or you have undersized 12 gauge wire and 20 amp breaker and the heat has loosened breaker on the busbar. Breaker trips when heat exceeds breaker limit. Jiggle breaker and listen for crackling sound.

To restore hot water now:
Turn off circuit breaker, and open top cover then Push in reset button on top of heater to restore functionality. Put back insulation and factory cover.
To fix water heater: test and replace bad element.
http://waterheatertimer.org/How-to-test-water-heater-element.html
If problems continue
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#trip-breaker
http://waterheatertimer.org/Troubleshoot-household-electricity.html

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

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

Error codes are start point for troubleshoot.
Error 14 is 'overheat wrap fault.'
This can include venting problem, failed heat exchanger, bad safety circuit, gas problem.
Rheem does not have a service manual posted for this specific problem.

Additional information: Tankless water heaters consume large amounts of gas during combustion. The combustion burns away hydrogen and the remaining poisonous byproduct is vented into the atmosphere at each home day and night.
Byproduct includes acidic water vapor that condenses along the vent pipe and drips back down vent.
Each tankless vent pipe has a drain line that directs acidic water into household drain.
If this drain line becomes clogged, or if vent was not installed correctly, then water drips down into heat exchanger and can erode or crack exchanger.
The typical maintenance manual above shows steps that can solve many tankless problems before they happen.

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

Error codes are start point for troubleshoot.
http://waterheatertimer.org/pdf/ErrorcodeTroubleshooting.pdf
Error 14 is 'overheat wrap fault.'
This can include venting problem, failed heat exchanger, bad safety circuit, gas problem.
Rheem does not have a service manual posted for this specific problem.

Additional information: Tankless water heaters consume large amounts of gas during combustion. The combustion burns away hydrogen and the remaining poisonous byproduct is vented into the atmosphere at each home day and night.
Byproduct includes acidic water vapor that condenses along the vent pipe and drips back down vent.
Each tankless vent pipe has a drain line that directs acidic water into household drain.
If this drain line becomes clogged, or if vent was not installed correctly, then water drips down into heat exchanger and can erode or crack exchanger.
The typical maintenance manual above shows steps that can solve many tankless problems before they happen.

THIS MAY NOT BE SAFE TO DO YOU CAN CALL THE MAKER

code 14 is a big deal shut that thing down! you will burn it up if you keep running it, your over heat wrap on the heat exchanger is too hot. call rheem they can walk you through it