Atwood water heater problem on gas

[Terry]

Well today is a great day! Unwinterize day!!

One problem - my Atwood DSI water heater won't start up on gas, but works on electric.

Here is what I see

- no spark, no gas
- connectors clean
- 12v showing at water heater on orange wire
- Eco and Tstat have continuity
- disconnected bottom wire harness and see 12 volts on the red wire pin which goes to gas valve
- connect wire harness and check red wire and it drops to 9 volts. (Checked with the red wire is disconnected from the gas valve) so it is not supplying enough to open the gas valve.

So at this point I think I have ruled out everything else so am leaning toward a bad board. Anyone else have any suggestions or other possibilities?

[Terry]

Ok I am just perplexed!

As I was working on the camper I noticed my radio presets were gone. Odd since I keep it plugged in all the time. Shut off the ac and the camper went dead. Traced it down to a corroded fuse holder at the battery. Cleaned it up (gunna replace it) and 12 volt power came back. Let the battery charge a little and poof - the water heater is working on gas.

This is very strange - I thought it would work just fine on converter only?

[David472]

I'm not familar with the particular trailer set-up, but some electrical systems run from the battery circuit always, and the inverter/charger serve the role to keep the battery up. They are configured this way, so that in the event of a shore supply outage, there is no real switch over to battery, because you're always on battery, so to speak.

So, that corroded fuse holder was adding resistance, resulting in the voltage drop under load. Likely the inverter/charger is on the battery side of that particular fuse, not the load side.

[Crabman]

Glad to hear ya got it workin`, tafische. Those dirty corroded connections will get ya every time! I have many issues like that in my boats with the harsh salt water environment. -Lee

[Terry]

Yeah Crabman...I am scratching my head a little on this one. I need to put a scope on my converter and see how dirty the power is. I would not think it IOTA converter would be that dirty, but maybe I am wrong. It has never given me a lick of trouble. What I find most odd is the voltage drop when I tried to measure the gas valve line...dont understand why it was so low when the converter is pumping out like 13.6 volts to the rest of the trailer.

Good news it is now working and I am ready to head out for the first time this year...only a few days to go....

As far as corrosion - I had an issue earlier this year where my terminals had a thin layer on them that was causing a voltage drop under load. Now I have an issue with my fuse, which I am going to replace - it was so bad it completely blocked any battery power going to the TT. This is not the big powdery corrosion, but rather the light film on everything.

What do you do to keep this to a minimum? I hear of people using Vaseline on the terminals...what have you found that helps?

[clutch]

So now you know what to do the next time it acts up.

[Crabman]

I haven`t had an issue on the 2 TT`s that I`ve owned with corrosion on the terminals, etc. yet. But I`ll look at them now and then after hearing this. On the boats, I just clean the battery terminals a few times a year and smear some marine grade grease on them. -Lee

[bulldogs116]

Not sure if this will work for you but give it a shot.

On my Motorhome I just sold I had an old timer show me this and it works even on the new TT.

When you want to light a gas piece of equipment. Try finding the the furthest distance such as a burner on the stove. Get that lit or run gas to it for awhile. Once that is lit then run gas to the other burners. This will get gas in the lines on your unit. Sometimes after not using the gas for awhile this seem to work. I used to manually light my hot water heater and fridge this way.....