Atwood gc10a-4e only producing luke warm water

5 years is about the lifespan for tankless.
You might have shorted element. That would explain cooler water and tripping reset.
Test element: power is off, disconnect wires from element; ohms = voltage squared divided by watt rating of element
http://waterheatertimer.org/How-to-test-water-heater-element.html

Call service technician./ Call Bosch
http://waterheatertimer.org/pdf/Bosch-AE115-AE125_manual.pdf

Gene

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

Open following link for Atwood water heater resources including parts list for different models:
http://waterheatertimer.org/Atwood-water-heater-resources.html

Following link shows ATWOOD Solenoid Gas Valve Type B - 93870
http://www.rvpartsoutlet.com/product_info.php?products_id=6268

There should be a temperature setting on the gas valve. It should be on top or front and have several settings normally vacation, warm and hot. Rotate dial towards hot setting to increase water temperature. Hope this helps. Thanks

suggestion, ck your electric element to see if worn out.
you can ck with an ohms tester for current.

If it is electric, It has an element. I would suggest that before reinstalling the unit, you make accommodations to make the next experience a little easier. Add an access door to the rear of the unit

Run it on propane and let water heater go through a heating cycle, and when it shuts off, CAREFULLY , pull the lever on the pressure relief valve slightly and see how hot the water feels there. If it's hot there, then it's more than likely a problem with your by-pass valve(s) at the back of the water heater. Either in the wrong position, or faulty, and allowing hot and cold to mix. If in doubt which one it may be, you may be able to remove by-pass set-up completely, depending on what system you have. What the ultimate goal is would be to attach your incoming cold line directly to bottom fitting of water heater, and outgoing hot line, to the top. Not unusual in some systems for one of the shut-offs in between the 2 lines to stay partially open, and allow cold to mix with hot, thus -warm only. If it's not hot at pressure relief valve, then I suspect a faulty thermostat, but that would mean they both (hydro and gas) would have to be faulty which is unlikely.

Also check that by-pass valve(s) is/are, in proper position at back of tank.

turn up the thermostat,, if that don't work, you need to replace the thermocoupling

you will need to have a 115 curent for electric, run a line off the panel box, turn off water to the house drain it down, disconnect the lp gas line and cap it off, remove the water heater, install the new heater run the cold side water to the cold side {blue on the heater} the hot side to the red, take the cover plate off on the water heater run the wires, hook up the groung wire then the red and white wires to the wires comming off the panel box,, fill the water heater with water have a open faucet on the hot side, and bleed the air out, DO NOT TURN ON ELECTRIC TILL THE AIR IS OUT OF TANK AND WATER IS FLOWING THRU COMPLETELY, after you get water commming out of the faucet turn it off and turn the electric on to the water heater ,, wait about 30 min, you will have warm after an hour it will be hot and you are done,, good luck write me if you have questions, [email protected]