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Jiri · 06-17-2021, 01:08 PM

I have a g6a-8e propane only water heater that works fine when connected to 12V dc but stops working as soon as connected to ac. There is 12.5 v at the control board input, whether the RV running using battery or ac power, but only works when ac is not connected. Everything else, fridge etc, runs well whether using dc or ac.

Old-Biscuit · 06-17-2021, 07:35 PM

Did to Measure the 'AC ripple' on the DC at water heater
6VAC Ripple or higher will cause issues with DC circuits

AC Ripple.....set Voltmeter to AC Volts Low scale then measure the DC at water heater

Converter is suppose to 'filter' AC ripple but if failing it will allow AC thru

Jiri · 06-18-2021, 02:34 PM

I am going to do it the next time I have the unit at home. I will let you know how it went.

Mudfrog · 06-18-2021, 03:17 PM

Quote:

Originally Posted by Jiri

I am going to do it the next time I have the unit at home. I will let you know how it went.

May not make a difference but I'll ask anyway. By any chance, are you turning the coach's battery disconnect switch off when you plug into shore power?

Old-Biscuit · 06-18-2021, 08:59 PM

Quote:

Originally Posted by Mudfrog

May not make a difference but I'll ask anyway. By any chance, are you turning the coach's battery disconnect switch off when you plug into shore power?

OP stated
There is 12.5 v at the control board input, whether the RV running using battery or ac power, but only works when ac is not connected. Everything else, fridge etc, runs well whether using dc or ac.

Mudfrog · 06-18-2021, 09:34 PM

Quote:

Originally Posted by Old-Biscuit

OP stated
There is 12.5 v at the control board input, whether the RV running using battery or ac power, but only works when ac is not connected. Everything else, fridge etc, runs well whether using dc or ac.

I'm probably using the wrong wording here but I believe there was a time that it was recommended to have batteries in the circuit to help "stabilize" voltage. My thought is that the the OP might have disconnected the batteries and that the water heater electronics don't like the voltage coming straight from the converter. Just an idea I thought I'd throw out..

Old-Biscuit · 06-18-2021, 10:25 PM

Quote:

Originally Posted by Mudfrog

I'm probably using the wrong wording here but I believe there was a time that it was recommended to have batteries in the circuit to help "stabilize" voltage. My thought is that the the OP might have disconnected the batteries and that the water heater electronics don't like the voltage coming straight from the converter. Just an idea I thought I'd throw out..

That would be the 'AC Ripple' OP needs to test for