My unit is a paloma tankless model # PTG-74PVP its throwing error code C4 15 what does this mean? We believe its a flow problem because we hooked up an external pump, it starts out with full flow then within a few seconds dwindles down to a trickle. Is there an internal filter that needs to be cleaned or changed? If so, where is it located in the unit?

http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html#flush

gene

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

Most likely dust in the combination fan or fan motor is dead

Hello Oumkaar Sharma,
Feb 2013

1) Copy following link for EcoSense-Rheem tankless resources:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

2) Error 13 is oxygen depletion sensor activated.
Get more fresh air to unit
Perform required maintenance.
Have qualified service technician test, clean, etc, and possibly replace burner.

3) Repair any brand tankless, same day, yourself for $368
http://waterheatertimer.org/How-to-install-gas-water-heater.html

4) Add a comment and say what you did to solve problem.

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

1) Check for crossover:
http://waterheatertimer.org/Crossover.html

2) Copy following link for Rheem Tankless resources including no-error-code:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

3) Add comment and say what you find.

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

Open following link for Rheem/Paloma/Richmond/Ruud tankless troubleshoot resources including error codes, self help, manuals, parts links, tips, and contact information.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Add a comment with your experience so others with same-similar problem can benefit.

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.

RTG-95XP Item Name: Outdoor Rheem Tankless Water Heater RTGL-74XP Item Price: $910-$1100 Gas Type: Propane Venting: No Item SKU: Rheem RTG-95XP replaces RTG-74XP Product Description: Rheem Tankless Water Heater RTG-95XP

Be aware of this --- http://www.cpsc.gov/cpscpub/prerel/prhtml07/07108.html

And this ---

Rheem RTG-95XP replaces RTG-74XP

This makes getting information hard to come by. Please use the link below for information.

http://www.rheemtanklessonline.com/contact.php

http://www.palomatankless.com/owners/homeowner+trouble.lasso#28-11
The Controller displays error code "1L."
There is a build-up of lime in your Paloma.
Contact your plumber to service the Paloma by flushing out the lime.
Also search u-tube for flushing lime out of tankless.

Rheem, Richmond, Ruud, and Paloma are all the same manufacturer. After about 9 months, my tankless RTG-74PVN started giving me error code 11 and cold water!. I fixed it by cleaning the burner, as shown in this video:
www.howtolou.com/clean-a-burner -Lou

Error code 76 indicates a communication error with the electronic board and the unit. Call Paloma/Rheem with the serial number and model number of your unit and they will, in most cases, send you a new board with instructions on how to easily replace the board.

Tech Support: 800-432-8373.

C8 is the last stop in the point of burner ignition and a total of eight error codes. Error code 12 is a supplemental code that means your LP gas supply is too low...have your LP tank service and try again.

HTH,

Mike...