SUBURBAN WATER HEATER HELP PLEASE

[Full_Time_Nomad]

Hi Everyone!
My 2000 Newmar Dutchstar has a 12g Suburban water heater that runs off propane & electric. When I purchased her, the electric mode did not work but the propane did and I was able to utilize all 12g of hot water. I recently decided to change the heating element so that I could run it off of electric. After replacing the old heating element with a new one, the hot water heats with electric but only lasts for 3min before starting to get cold....OK not ideal but I figured that I would just keep using propane because it WAS working just fine. HOWEVER, now the hot water only lasts for about 2 gallons while heated by propane. UGH! So now I am at a loss of what do try next. Any advice is appreciated!

 

[Sealyn]

Check the valves to be sure it isn't bypassed.

 

[Full_Time_Nomad]

Check the valves to be sure it isn't bypassed.

Writing this because I am trying to learn but I don't understand how the propane worked completely fine until I changed the electric element. I didn't touch any of the valves when I did the swap, so why would the valves be an issue now?

 

[TheLooks]

Have you used the outside shower recently? IF you just shut off the shower head button and left the hot and cold in the on position, it will syphon thru and cause this.

 

[TheLooks]

Take a picture of the backside of the heater and post it.

 

[Full_Time_Nomad]

Have you used the outside shower recently? IF you just shut off the shower head button and left the hot and cold in the on position, it will syphon thru and cause this.

I have not used the outside shower. Thanks for offering a solution.

 

[Full_Time_Nomad]

Take a picture of the backside of the heater and post it.

 

[osuallen]

Maybe I am incorrectly filling the gaps of the outlet and valve not in the view, but this appears to be partially bypassed. I am interpreting the valve in the center in the red line to be the bypass line and it appears to be open. Likewise, I am assuming the valve on the lower right to be the inlet and that valve appears to be off. Finally, i am assuming the clear line at the bottom is not to/from the water heater and it goes around the inlet valve and does not tie to it. Am I interpreting the lines and valves correctly?

 

[TheLooks]

No, it is correct. The one in the clear line is closed.

 

[TheLooks]

If the propane is not heating the water up, it must be shutting off to soon. This would indicate a problem with the thermostat. Both the heating functions work off the same thermostat and high temp cut off. The board selects the one to use or both.

 

[Full_Time_Nomad]

If the propane is not heating the water up, it must be shutting off to soon. This would indicate a problem with the thermostat. Both the heating functions work off the same thermostat and high temp cut off. The board selects the one to use or both.

I think this is my next move to try. I will update everyone if the thermostat solves the issue.

 

[TheLooks]

If you have access to a laser thermostat it will make testing easy. The thermostat runs on 12v so if it stops passing voltage and the water is not hot it has failed. Test both of them as they are in series connection.

Laser thermometer. Doh...