Water heater works on 15A not 30A?

[fuddyq]

Hello all!

After getting our trailer out of storage, the Atwood water heater only stays lit if I?m connected to 15A. If I?m on 30A it fires, the circuit board makes some beeps and shuts itself off and gives up after three tries. Our furnace, too, only lit and stayed lit once, when we had no power at all.

Any ideas as to why?

It?s five years old, I switched out all the fuses, and even changed out the connection bits on the outside of the water heater. Propane isn?t the culprit because it?s working fine for fridge and stove.

Thanks for any ideas!

 

[darsben]

Have you determined if the 30 amp supply is wired correctly?  Could be hot and neutral are reversed on the 30 amp outlet

 

[SeilerBird]

It sounds like you are plugged into 220 volts. Is this the dryer outlet you are plugged into?

 

[fuddyq]

We are at a different spot right now, but the place we noticed the 15A worked had a breaker that allowed me to change from 30 to 15.  Not sure why we tried it but it worked flawlessly. Of course then the microwave and AC didn?t, but we would just switch it back after washing dishes or showering.

So the 30A at that place didn?t work and the 30A here isn?t working either. It?s very strange. Which is why I don?t think it?s the outlet/supply.

SeilerBird: if you mean ?does the outlet look like a dryer outlet? yes it does. But it?s not plugged in at home like that. I usually just use a converter to switch to regular three-prong while it?s parked outside the house to get the fridge cooling.

I?m no electrician but it feels like maybe the 30A is too much for the water heater (specifically the circuit board, so perhaps something is wonky on it) and it?s stopping the propane for safety. And yet, 15A is fine.

 

[Roy M]

It will only draw what it needs so 30A won't hurt anything. Excess voltage is another game altogether. Something is wrong with your connection.

 

[grashley]

The water heater does NOT need 120V power to run on propane.  It DOES need 12V power.  This can be supplied by a charged battery and / or a converter, which converts 120VAC to 12VDC to charge the battery.  The furnace requires no 120V power - ever.  It runs on 12V and propane.

Do other 120V items work on 30A power?  15A power?  Items include the microwave or anything plugged into a 120V outlet (light or fan).  I do not know how having 120V power could mess-up the 12V power supply unless the converter was putting out too much voltage ????

With the camper unplugged, measure the battery voltage with a cheap voltmeter.  It should be about 12.6V for a fully charged battery.  Plug the camper into 120V 15A power and repeat this reading.  If the converter is functioning properly, you should read about 13.5V or more.  Switch to 120V 30A and repeat.

As Roy said, too many amps is never a problem.  Using water as a poor example, if you need 5 gallons per minute (gpm) to water the flowers, but the ?" hose can only deliver 3 gpm, then 3 gpm is all you get.  If you are connected to a 100 gpm fire hose and your nozzle can only deliver 5 gpm, then 5 gpm is all you get.  The hose can also deliver water simultaneously to other water users.