RV Repair: Battery and water heater problems, water heater problems, nomad dealer

Question
I have a 2004 24lt Nomad travel trailer and the battery only lasts 2 days even if we don't use lights or water pump. I have burned up 2 water heater circuit boards at $180.00 each.  The Nomad dealer told me the reason that the circuit board is burning out is that there isn't enough battery power to electronically ignite the heater although it keeps trying.  Do you think there is an abnormal draw on the battery?  How do I check?  I don't know where to start.

Answer
Hi Dee,
 How old is the battery? If it is fairly new and you are still having a draw problem. You can at least find out what wire is drawing the battery down by doing the fallowing.
 Turn off all 12 volt lights and appliances. Get a 12 volt test light. Be sure it works. Disconnect the ground lug from the battery. Hook one end of the tester to the loose end of the neg. battery wire. Tape the other end of the tester to the neg. battery post. The draw will light the test light by the current running through it. Go to the fuse box and pull one at a time the 12 volt fuses. When the light turns off you will know that that wire is the source of the draw. Read what is powered on that wire and inspect those things to fix the problem. Good Luck.