No Voltage to Tankess Hotwater Heater Bathroom Controller

[JJ50325]

Hi All -
Was wondering if anyone else has had this problem and a workable solution:

We have:
2023 Solitude 310GK. This coach has not been used much. It sits in an enclosed and heated RV barn. Never been winterized and never been used in the cold. Everything worked perfectly when we came back from a trip to AZ for 6 weeks. However we did NOT used the tankless water heater when we got back to the house and cleaned the coach before moving it back to the RV barn.

Problem - Just came back from this trailers third trip since purchase. Replaced the 4 wet cell golf cart batteries with an Epoch 460ah lithium and replaced the WFCO controller with a Progressive Dynamics PD9630 Converter. After the new battery was placed in the battery compartment, everything tested out in the coach EXCEPT the tankless hotwater heater. The controller on the bathroom wall would not initialize.
Checked outside on the control board and 12v electric everywhere worked. Power coming in had 12v and the two blue wires (for the wall controller) going out had 12v on the board. Crawled inside/underneath and tested the voltage on white and black wires on the back on the unit. They both measured at 12v. The two blue wires on the back of the unit also tested at 12v. Then headed upstairs to the bathroom to test the two wires coming into the tankless water heater control unit hanging on the wall. Here lies the problem. NO voltage coming into the unit.

Has anybody else had his problem and if so how did you fix????

I believe this on is going to be hard to work on. All of the wires go up the wall. There is no access. There is a light switch on the opposite of the wall for the bedroom lights. They are on the 12v coach circuit. Can this be tapped into to make the wall controller work?

Any help offered will be considered.

JJ

 

[llr2800]

Did you possibly turn the switch off on the water heater itself. I have not used the WH yet but noticed the panel was dead after turning the switch off.

At least on mine it is getting power from the WH. I would start with connections on each end. It is rare for the wire itself to have an issue.

 

[JJ50325]

llr2800
Finding the the Power Switch on the front tankless water heater (TWH) in the "O" position would have been waaay tooo convenient.
As mentioned previously, I have checked the power line coming into the Control Panel for voltage, inside the Control Circuit Board for voltage, the power lines going from the back of the TWH, as well as the two little blue wires that go to the back of the TWH from inside of the TWH Control Circuit Board for voltage. Everything tests out with voltage on my voltmeter EXCEPT to the two wire connecting to the back of the Controller that hangs on the wall in the bathroom.
And 'Yes" I agree with you about the rarity of not having power to these two end wires. It seems those two wires run everywhere from the back of the TWH to wire bundles up to the ceiling and then down an interior wall to the bathroom. These wires don't move, so I find the no voltage at the end extremely hard to understand.
Thanks for your response.
Will keep testing. Keeps my #1 girlfriend from hassling at me too much!!
J.J.