I have a bosh water heater WR4001K-LP. It has a regulator attached a maxitrol RV48L, 1/2 psig, pa 5.0" - 12.0". Do I need a regulator at the propane tank as well? If so what kind ? Thanks

Pressure from a gravity system can only come from the height of the water tank above the height of the inlet to the heater. This difference is called "head". To get more pressure you need a greater head. You will need to raise the tank a minimum of 3'. Note: you could test the pressure using a hose, head is based on vertical height of water, and has nothing to do with volume of water.

Rheem water heaters should not be converted from propane to natural gas. The burners have been optimized for the rated gas and will not work as well after conversion. (Unlike ranges where the gas/air flow ratios can be adjusted when the burner orifices and regulator are swapped, the water heater doesn't have that option.)

I wish I had better news for you. I recommend you get a new water heater for the LNG service; it will be safer and more efficient.

Cindy Wells

No you need to replace that valve.

Before calling service technician, open following link for Rheem troubleshooting resources:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Error codes are consider start-point for troubleshooting:
Following example information might help.
http://waterheatertimer.org/pdf/Error-code-13.pdf

sounds like the generator has packed up. check water flow and clean any filters on the water line. you will need a service agent to check milli volts on generator and power pack

Propane is liquid in your tank. The vapor pressure will depend on the temperature as you can see by the following chart. For an example at 0F the vapor pressure in the tank would be 24.5 psig. and at 90F it would be 150psig. This is why you draw vapor from the top of the tank and then go immediately go through a high pressure regulator. Then usually at the appliance there is also a regulator (sometimes incorporated in the safety valve) You are burning propane as a vapor not a liquid. Remember for safety that propane vapor is heavier than air and sinks to the floor, so one must be careful for proper ventilation.
Temperature vs Vapor Pressure
(oF) (oC) (psig) (bar)
-44 1) -42.2 0 0
-30 -34.4 6.8 0.5
-20 -28.9 11.5 0.8
-10 -23.3 17.5 1.2
0 - 17.8 24.5 1.7
10 -12.2 34 2.3
20 -6.7 42 2.9
30 -1.1 53 3.7
40 4.4 65 4.5
50 10.0 78 5.4
60 15.6 93 6.4
70 21.1 110 7.6
80 26.7 128 8.8
90 32.2 150 10.3
100 37.8 177 12.2
110 43.3 204 14.1

BOSH AQ 250 On demand propane water heater ran out of propane, got gas now, but get EC flashing on the display and the unit won't fire? Lost manual, any suggestions. Thanks, Jim

lpg overgassing best leave to the experts

No, you can adjust the water temp though.

did you check to see if your temp regulater is working properly? also you have a thermocoupler that senses the heat of the water and works in conjunction with the regulator. have either one or both replaced and the problem will be solved. please rate this thanks