Had a new heater element installed. won't go

check circulation pump if running check pressure switch circuit make sure unit isnt on maintain mode or economy

either its the oven sensor rod located at the top of the ovens cavity,or your bake element could be getting a hot spot which is when it gets a discolored spot in the element and can no longer pass sufficient current to heat the oven past 250 degrees

you shouldn't have to set your heater to 135. dishwashers have a built in heating element for just this purpose.

once you start going over 120 degrees on your water heater, you start creating scalding problems.
130 degree water can cause second degree burns in 30 seconds
140 degree water can cause second degree and even third degree burns in 6 seconds
150 degree water can cause third degree burns in 2 seconds.

be very careful !

Your temp sensor has gone bad. This is a small tube with wires coming from it. You will find this on the left side of the water manifold. Follow the wires to the front of the heater and unplug it from the temp board. Install the new one in the reverse fation. good luck.

it's most likely a temperature sensor, what is the readout on the top side control?

http://www.rheemtankless.com/content/tankless/rheem/help.shtml

This is there website.Above.
Use the live chat to ask them, the code you listed does not seem to correspond to there code list, the only code that does is code 76,
which is a problem with the remote control not talking to the unit.
So your best bet is to tell them the error.

refere to glowworm expert advise

It is advisable to replace stats after fitting new element, make sure there is no build off lint round the stats.. Hope this helps