Replacing An Old Atwood Water Heater With A Fogatti Tankless Water Heater

Published 04/22/2024

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Digital Multimeter with 42" Long Test Leads - LED Display

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Question:

Hello Kevin, hope this finds you in sound health and in great spirits. I am swapping out my old 6 gal Atwood water heater to Fogatti instant 8 pro in my 2018 Winnebago View 24V. Fogatti instant 8 pro has 4 wires coming out - 2 blues for the control, and a black and a white wire. My 2018 Winnebago View 24V RV has 4 colored wires -Blue, Orange, Green and a White. I am totally confused which colored wires from the RV to connect to the Black (labeled 12v) and White of the water heater! Please Help! Much obliged in advance!

asked by: Tashi G

Expert Reply:

Hey Tashi,

Your Fogatti wtare heater # LSB64FR is going to have a red wire to run to a 12v power source, black wire for your negative that you can just run to the frame with a ring terminal, and two blue wires that need to connect to the two blue wires on the remote. It doesn't matter which blue wire goes to which blue wire on the remote but they can never touch.

As for the old wiring you'll need to test each wire with a multimeter # PT89ZR and see which is the power. The rest of the wires are likely just communication wires between the unit and remote and can just be capped off with electrical tape. If your old unit ran off of 120v then you'll need to run new wire to either the battery or a DC distribution panel to power the new water heater.

expert reply by: Kevin C

Wire Diagram
(click to enlarge)

Tashi G.

4/22/2024

Hello Kevin, thank you so much for getting back with me. It is a InstaShower 8Pro, 55,000 BTU RV Tankless Water Heater that only has a Black (labeled 12V) and a White wire, No Red wire from the Fogatti. How can I tell if the old water heater ran off 120v? Thank you again in advance! Best

Kevin C.

4/22/2024

@TashiG The old Atwood heater should have a sticker on it listing the voltage requirements or you can just test the wires with a multimeter # PT89ZR and see what the voltage is on the wire. There should be no power on the communication wires or ground so only one should have a power reading. You can also look at your AC and DC distribution panels. If your water heater is on a circuit breaker like you'd see in your house then we know it's AC (120v). If you find it running to a fuse like you'd see in your car then we know it's DC (12v).

Tashi G.

4/22/2024

@KevinC thank you so much Kevin. You are truly a lifesaver. Have a blessed day!