Need help tankless install electrical

[MnemonicGhost]

I have a m349 that came with a standard gas/elec water heater. I swapped it out for a tankless from Ranein (basically a copy of the fogatti). Install went fine buuut now I have hit a snag.

When I use the one control panel to turn the gas water heater on I get full power from the new tankless. But as soon as I turn the faucet on and trigger the tankless to heat the water the one control panel shuts off the gas water heater.

I thought this was a water heater issue. So I wired it directly to the 12v battery and the tankless worked flawlessly. The issue seems to be when I connect it to the existing wires from the old heater that the one control panel seems to shut off power once the unit tries to turn the gas on.

If it's relevant or not my hot 12v wire is red and my ground is green. There is an orange wire (not used) that shows .46v and a blue or purple wire that may also be a ground but doesn't operate as one. And yes I swapped the wires all around to get it to work right and it only works when red is 12v and green is ground. But as soon as the unit tried to start heating the one control shuts it off.

I know it's the panel because the panel shuts the gas water heater off and then the unit itself will lose power. There and no tripped or blown fuses and like I said it runs perfect when directly connected to a 12v battery.

Thanks for any help

 

[Scott'n'Wendy]

I don't have a tankless nor does my one control panel control our water heater. So just thinking out loud.
Connecting directly to battery confirms the WH is good so the problem must be the wiring. Were all four wires you describe all connected to the original heater? With my heater the water heater can be inhibited by an ignition fault. Is it possible the One control board sees a DSI fault? Maybe the orange wire is a signal wire back to the board to show proven flame. If the board doesn't get proof of flame it shuts down the power?

 

[Second Chance]

You might contact Lippert customer support, but I doubt that the One Control system is designed to work with other manufacturer's water heaters - especially if the system was installed with firmware for tank WH and you're swapping for a tankless.

Rob

 

[Cpadd23]

I have a m349 that came with a standard gas/elec water heater. I swapped it out for a tankless from Ranein (basically a copy of the fogatti). Install went fine buuut now I have hit a snag.

When I use the one control panel to turn the gas water heater on I get full power from the new tankless. But as soon as I turn the faucet on and trigger the tankless to heat the water the one control panel shuts off the gas water heater.

I thought this was a water heater issue. So I wired it directly to the 12v battery and the tankless worked flawlessly. The issue seems to be when I connect it to the existing wires from the old heater that the one control panel seems to shut off power once the unit tries to turn the gas on.

If it's relevant or not my hot 12v wire is red and my ground is green. There is an orange wire (not used) that shows .46v and a blue or purple wire that may also be a ground but doesn't operate as one. And yes I swapped the wires all around to get it to work right and it only works when red is 12v and green is ground. But as soon as the unit tried to start heating the one control shuts it off.

I know it's the panel because the panel shuts the gas water heater off and then the unit itself will lose power. There and no tripped or blown fuses and like I said it runs perfect when directly connected to a 12v battery.

Thanks for any help

I replaced a water heater with a tankless last summer and had a similar problem. Seems there is a DSI circuit with the old gas unit and it senses the gas ignition system as I best understand. The cure that worked after I researched the problem involves the ground in the old tank heater system. I grounded the tankless water heater to the rv frame not the water heater wiring and works well.

 

[MnemonicGhost]

I will try all these solutions before I just run a separate switch to battery directly. I assumed there was a internal check happening but wasn't sure. I appreciate the help.