Xerox 2515 problem

Get in touch with the friendly Xerox Engineer, I think I remember this error code being the Cyan print head is not performing as it should. A bad batch of Cyan was allowed onto the market a lot time back and the plumbing and print heads became bunged up, due to crystallisation within the hot wax.
Hope you have a service contract!
Good Luck.

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.

Code U4-1 is Over heat or under heat, even if you solve this problem you mentioned that you have a copy from the machine which is Blank, the reason is that the print cartridge is dead, it is not holding charge, and even if you find a new one in a box sealed, I am 99.9 present sure that it is not going to work either, it is an old expired cartridge, basically do not waist your time and money, I serviced these machines and I know.

This will most likely clear it. If not then the heat rod in the fuser most likely went bad.
Performing a Fault Reset 14 will reset your copier and will help to clear error codes.

1. Turn the power off.
2. Locate the Clear Button, which is grey in color, in the upper right corner above the green Start Button.
3. Locate the Auto Button the lower left corner of the Control Panel.
4. Turn the power back on.
5. Press the buttons in the following sequence, releasing each button after each time you press it: [Clear], [Auto], [Clear], [Auto]. Every light on the Control Panel should go out, and the error code should clear.
6. Program the copier as if you were going to make 14 copies.
7. Press the green [Start] button to store the reset code. The copier will return to the ready position.
8. Run a test copy.
9. repeat 1-7 more than once to be sure it has worked properly.

There was incorrect info in this I copied and pasted. I corrected it.

this error comes from fuser unit u have to change fuser unit

I had one today with a toner low light with new toner installed. Turns out they broke the green cartridge retainer clip.
The toner sensor pn# 130K45680 btw.
let us know if it was the sensor.

Paper goes on the bottom first. original goes in top next

the first step is to pull the paper out and see if the feed rollers have left a mark on the paper that would mean your rollers are turning just not picking up the paper if this is the case remove the paper tray and with a wet rag clean the feed rollers always easier with a flash light keep in mind they may need to be replaced call 7734748865 il b happy to help

From the service manual:

Code 83: Engine NVRAM is corrupted or receiving wrong data from a CRUM.

1 Cycle power to the printer. Does the error still appear? If so, go to step 2.

2 Remove and reinstall the Imaging Unit and Fuser Assembly. Does the error recur
after the power has been turned off and then on? If so, go to step 3.

3 Replace the imaging unit. Does the error still occur? If so, go to step 4.

4 Replace the fuser assembly. Does the error still occur? If so, to to step 5

5 Replace the EEPROM board. Does the error still occur? If so, replace the Engine Control Board.

NOTE: Some Status codes will not clear even though the problem has been fixed. Status codes that will not clear must be manually reset using the 'Fault Reset 14 Procedure'.

1. Locate the [C] (Clear) button on the Control Panel, at the far right.
2. Locate the Image Quality button, below the Auto on the Control Panel, toward the left side.
3. Press the buttons in the following sequence within 4 seconds. Press [C] (Clear), press [Image Quality], press [C] (Clear) again, press [Image Quality] again.
4. The error code should disappear. If the Status code does not clear, repeat step 3 until the status code clears; but no more than five times.
5. Use the [10] and [1] buttons to enter 14 on the Display Screen, as if you were to make 14 copies.
6. Press the [Start] button. The machine should be ready to use.
7. Make a copy, to check that the machine is working properly

IF these steps do not work you will have to replace the fuser or fuser heat rod then perform the reset.