No hot water error codes 76, C4,C7 - Rheem RTG-66DVN Direct Vent Natural Gas

Richland tankless is made by Rheem.
C7-76 is communication fault with remote.
Turn off power at remote and wait 5 minutes, turn power back on at remote, and see if problem clears.
If problem continues, read below:

Before calling service technician, open following links for troubleshoot resources including error codes, Rheem chat, typical maintenance manual:
http://waterheatertimer.org/pdf/Rheem-error-code-C7-76.pdf
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Tankless water heater, more than any other type of heater, need to be maintained.
Maintaining tankless will probably not affect C7 76 fault code, but can prevent many other common error codes.
http://waterheatertimer.org/pdf/Tankless-maintenance.pdf

1) Before calling service technician who can test parts, open following link for Rheem resources including error codes, Rheem chat and phone number, possible manual:
If local technician cannot solve problem, Rheem can probably recommend a person.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

2) Error codes are start-point for troubleshooting.

3) Multiple error codes can indicate PC board failure.
If your computer motherboard fails, most people feel the computer is compromised even after motherboard replacement.

4) Error code C7-76 is communication error with remote, and can include bad remote, bad wire to remote, loose wire, or bad PC board.
http://waterheatertimer.org/pdf/Rheem-error-code-C7-76.pdf

5) Error C4-13 can include part failure, vent problem, oxygen depletion, and can also include PC board failure.
http://waterheatertimer.org/pdf/Error-code-13.pdf

6) Tankless routine maintenance manual:
http://waterheatertimer.org/pdf/Tankless-maintenance.pdf

7) Some posts about tankless concede that qualified technician was unable to repair unit.
Solve most tankless problems yourself, same day, for about $350.
http://waterheatertimer.org/How-to-install-gas-water-heater.html

8) Take a moment and rate answer:
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Before calling service technician, open following links for troubleshooting resources:
http://waterheatertimer.org/pdf/Rheem-error-code-C7-76.pdf
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Before calling service technician, open following link for Rheem troubleshoot resources including error codes and typical manuals.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html
C7 76 is problem with remote control. Following link might help.
http://waterheatertimer.org/pdf/Rheem-error-code-C7-76.pdf

Read manual cover-to-cover to make sure your tankless water heater receives yearly maintenance required for unit to continue working.
Tankless are maintenance heavy which can quickly eliminate any promised energy savings unless you de-lime and troubleshoot and read tips-and-tricks others have written and glean information from service technician who visits your house. Mostly glean how much tankless repairs and parts cost vrs buying whole new tank-type gas water heater at local box store, since all costs are energy.

Use following link for Rheem tankless troubleshoot: http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

I believe error code C7 is same as error code 76
http://waterheatertimer.org/pdf/Rheem-error-code-C7-76.pdf

Add a comment for more free help.
Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Remove power source from the unit. If remote control is installed; remove cover and lift the control wires on the terminal...can be accomplished from either end.

Restore power and see if unit functions normally.

Contact Paloma/Rheem customer (800-432-8373) support and notify them IF you are getting a code "76" error. Rheem has recently extended the warranty on the "Burner Control Assm."; which is your problem. The C4-C8 portion of the error code, is where the unit stops the ignition process...burner fails to light, or gives you intermittent hot water. In either case, contact customer support .

If this helps, please indicate so.
Mike//jzklipper

faulty fan

Contact Paloma/Rheem customer (800-432-8373) support and notify them you are getting a code "76" error. Rheem has recently extended the warranty on the "Burner Control Assm."; which is your problem. The C4-C8 portion of the error code, is where the unit stops the ignition process...burner fails to light, or gives you intermittent hot water. In either case, contact customer support. However, I do have a detailed process on how to repair the printed circuit board yourself. Any further questions, you're welcome to email me at [email protected] .

Good Luck, if this has helped you in any way...please indicate so.

If you look on the left hand side of the burner control module you'll see 4 capacitors - the capacitors have most likely failed...pretty sure anything code 76 is P/S failure. It may also be covered for manufactures defects. If the cap is blown..the top will be slightly raised as apposed to flat like the other nearby caps - they are called top blow capacitors...the damage should be evident.

I had the same problem with my tankless waterheater (flashing c4 76 alternately). I called Rheem
tech support and they had me 1 power down the remotepanel 2 unplug the unit from the wall 3 remove the cover 4 remove the wires for the remote panel from the circuit board and pull the twisted pair that goes to the remote out from the bottom of the unit. 5 reinstall the cover 6 plug the unit back
into the wall and turn on the hot water see if it works. It did in my case and they are sending me a new remote panel. I hope it helps.........