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paul55 · 04-25-2012, 07:59 PM

I have a 1980 31' International center bath that the Bowen gas water heater has finally given up and I want to replace with a gas/electric with electronic ignition, but there is no 12v for the ignitor nor 120v for the element under the bathroom sink where the heater is located. I've pulled out the water heater and don't see any wires in the walls either. Does anyone have any experience or suggestions for getting 12v and120v to the new water heater? The breaker box is on the street side and the water heater is on the curb side. Do I have to run a dedicated circuit? Thanks

Splitrock · 04-25-2012, 08:11 PM

I got the 12 volt from the bedroom light. There's a 120 volt outlet on the same side under the kitchen sink base. I thought of running a cord to that and put a switch with indicator light under the sink base.

Aage · 04-25-2012, 08:13 PM

Why bother getting a 120V unit? Get a gas only model; it's cheaper to buy, and far more simple to install.

You will only need one single 12V lead, since the shell is at ground potential. You are never far from a 12V connection in an Airstream...

The annual savings that 120V will give you will be negligible unless you are living in it full time.

paul55 · 04-26-2012, 08:24 AM

Thanks for the replies, I don't see a 120 outlet under the kitchen sink, but I believe I may be able to tap the outside 120v outlet, which is about 5 feet from the water heater and run the 120v between the inner and outer skins and I did find a small 12v light under the rear bed next to the outside access door that I didn't even know was there. I just think having the option to use the electric element in a campground, or off a generator, or if I happen to run out of propane, is a good thing to have. Thanks again.

Minno · 04-26-2012, 09:28 AM

If you're installing a water heater with electronic ignition, you will need to install the switch for the water heater as well as the 120 volt switch. Plus, new water heaters with electronic ignition also have a indicator light, typically built into the switch. If the water heater fails to light while in gas mode, the indicator light will illuminate. So, you actually will need to connect 3 wires from the water heater, plus the 120 VAC wires. The 3 "12 volt" wires are ground/return (white), + 12v power from the switch, and then the indicator wire that lights the light. You'll need to read the instructions to see what color wire is which for those two. The easiest thing to do would be to install the switches for the water heater close to the water heater's location - perhaps even in the same cabinet if you can.

Chris

Splitrock · 04-26-2012, 09:30 AM

The other obvious 120 volt solution, would be to add a second shore 120 volt receptacle and add a second 120 volt supply cord to a split campsite supply outlet. The split could be fused without any problem. That way, there'd be no additional load on the coach fuse box. The marine supply sites have good solutions to the receptacle issue.

Maybe some of our marine friends will supply a link or two.

`

paul55 · 04-26-2012, 12:52 PM

the atwwood replacement I bought has a duel switch with an indicator light and it operates both the the 12v ignitor and the 120v element and the instructions seem pretty straight forward, I'll probably mount the switch in the bathroom cabinet. I thought about just running another cord to shore power to take the load off the 30amp system and I am leaning in that direction, not so much for an easier install, but because of the safety factor, although I'd rather just have one cord out. I read about folks upgrading to 50amps, but not ready to make that change just yet. thanks for all your help, if any other thoughts/ideas come up, please let me know

paul55 · 04-26-2012, 01:33 PM

Another idea for the 120v, and maybe this is what you meant, I could run romex under the rear beds and around the back to the electrical box the shore cord ties into and make a jumper from there to a separate small breaker box just for the water heater, and bypass the coach breaker panel all together.

Splitrock · 04-26-2012, 07:22 PM

Quote:

Originally Posted by paul55

Another idea for the 120v, and maybe this is what you meant, I could run romex under the rear beds and around the back to the electrical box the shore cord ties into and make a jumper from there to a separate small breaker box just for the water heater, and bypass the coach breaker panel all together.

That's not what I was writing about, but it may work okay. I'll just plug mine in and switch it. If it blows a breaker, I'll just run a separate power cord that exits the coach near the location of the water heater. I doubt I'll use the 120 volt feature much. I doubt I'll use the trailer much.

`

Minno · 04-27-2012, 06:35 AM

Quote:

Originally Posted by paul55

Another idea for the 120v, and maybe this is what you meant, I could run romex under the rear beds and around the back to the electrical box the shore cord ties into and make a jumper from there to a separate small breaker box just for the water heater, and bypass the coach breaker panel all together.

Do NOT bypass the main 30 amp breaker! In other words, if you're thinking about splicing into the shore power cord before it enters the main beaker box to go to a second breaker box, don't. That would bypass the main beaker to get to the second breaker box, which means you run the risk of drawing more than 30 amps on your shore power cord. More than 30 amps would cause the cord to overheat, and potentially melt or char the insulation. Worse case, start a fire. Not good...

If you're going to install a second breaker box for the water heater, tap into the main breaker box after the main breaker.

If you can run new romex back to the main breaker box, a better option would be to remove one of the full size 20 amp breakers and install a twin 20 amp breaker in its place. This will give you two breakers in the space of one old one. Connect the water heater one of the twin breakers, and the original wire to the other one. Just make sure you buy the right brand twin breaker. Bring the old one with you if you're not sure what brand it is, and they can help you at the store.

If you have questions on how to do this, post some pictures of your breaker box, and we can help you.

Chris

paul55 · 04-27-2012, 10:46 PM

Quote:

Originally Posted by Minno

Do NOT bypass the main 30 amp breaker! In other words, if you're thinking about splicing into the shore power cord before it enters the main beaker box to go to a second breaker box, don't. That would bypass the main beaker to get to the second breaker box, which means you run the risk of drawing more than 30 amps on your shore power cord. More than 30 amps would cause the cord to overheat, and potentially melt or char the insulation. Worse case, start a fire. Not good...

If you're going to install a second breaker box for the water heater, tap into the main breaker box after the main breaker.

If you can run new romex back to the main breaker box, a better option would be to remove one of the full size 20 amp breakers and install a twin 20 amp breaker in its place. This will give you two breakers in the space of one old one. Connect the water heater one of the twin breakers, and the original wire to the other one. Just make sure you buy the right brand twin breaker. Bring the old one with you if you're not sure what brand it is, and they can help you at the store.

If you have questions on how to do this, post some pictures of your breaker box, and we can help you.

Chris

Thanks Chris, I guess my thought was that with a1400 watt element in the water heater that will draw less than 12 amps (when it cycles) I wouldn't exceed 30 total amps even with the a/c running (about 10 to 12 amps) so it wouldn't matter if I was before or after the 30 amp main. If the shore cord is an issue, would going to a 50 amp cable be an answer? From some reason my "main" is currently a 20 amp breaker that I was going to replace, but would leaving it give me a "safety factor" if I went the route I mentioned, with a 15 amp breaker in the 2nd panel?

Minno · 04-28-2012, 09:14 AM

From an electrical capacity point of view, 20 amps plus 15 amps is 35 amps, which still exceeds the 30 amp capacity of the cord. While you may never exceed 30 amps total, you can’t guarantee that, and you still have the potential of running 35 amps through your shore power cord.

Options that I see:

1. Replace the main with a 30 amp breaker, and use a twin 20 amp breaker like I mentioned above. This is the easiest option as far as the shore power cord goes, as you don’t need to do anything with it. That’s assuming that it’s a real 30 amp, 10 Gauge RV shore power cord, and not some smaller wire size. If it is a smaller wire size, then it will need to be replaced no matter what you do.

2. Replace the shore power cord with a 50 amp cord. Connect the black wire in the 50 amp cord to the original main breaker, and connect the red wire to the new 15 amp breaker in the new box. Connect the white and ground (green or bare) to both breaker boxes. This will allow the water heater to run off the second power leg of the 50 amp power cord. No chance of overloading the power cord in this scenario. You can replace the main 20 amp breaker with a 30 amp breaker if you want as well. If you use a 50 amp to 30 amp converter plug because the campground does not have 50 amp service, then you will still have 30 amp service to the main breaker, but the water heater will not work on electric.

3. Replace the shore power cord with 8 gauge wire and then wire it like you suggest. The combination of a 20 amp breaker and 15 amp breaker (35 amps total) will not overload 8 gauge wire. 30 amp campground power outlets will be protected with a 30 amp breaker, so you won’t be able to exceed 30 amps anyway. But, if you run into a campground that only offers 50 amp service, then you’ll need a 50 amp to 30 amp converter to plug in. Good idea to carry one with you anyway just in case. Since the outlet is protected with a 50 amp breaker, you could draw 35 amps on the power cord in an extreme condition, but the 8 gauge wire will handle that ok. The biggest drawback with this option is that you’ll have to build your own shore power cord, and even if you do, the plug is only rated for 30 amps. So, you still have the potential for exceeding the current capacity of the power plug itself, which can result in overheating and melting. For this reason alone, this option is not something I would recommend.

Chris

paul55 · 04-28-2012, 09:55 AM

Sounds like the easiest option for now is to change the main to a 30 amp and wire the water heater up to a new double 20 amp breaker, since all my slots are full. Thanks for all you help Chris.

Bill M. · 04-28-2012, 11:36 AM

I put in a gas/electric heater as a replacement. If I had it to do again I would just get the gas. I put a male receptable on the lead for the water heater, put in a plug in GFI on it, an plug it into the extra 20 amp outlet that is on most campground electircal boxes now. What I end up doing most of the time is just running the gas wh for about an hour in the am and the pm. I am probably even going to quit carrying the extension cord I bought just for the wh.

paul55 · 04-29-2012, 05:32 PM

I got the water heater wired up as Chris suggested, replaced my main with a 30 amp breaker and ran romex to a new double 20 amp breaker. I fired up the gas burner and had hot water in no time. That's the good part of the story. I thought since I had my gas hooked up I would go ahead and check out the stove and heater. (i had a "systems check" at the local Airstream dealer last November and they said everything was good to go except the water pump, which i replaced and has been working fine, the water heater sprang a leak after I got it back home) The stove top and oven worked fine and the heater blower ran but the burner never lit

paul55 · 04-29-2012, 05:37 PM

and now my water pump and lights over the sink dont work, but i have no blown fuses. I see no orange wire in the fuse box which is what the water pump is hooked to, any suggestions on trouble shooting this problem are appreciated.

Splitrock · 04-29-2012, 06:04 PM

Check for power using a jumper light or a multi-meter. Start with the converter. Is it working? Check the fuses by objective test, not just by looking.

paul55 · 04-29-2012, 06:18 PM

Found my problem with a meter, All the fuses looked good but the number 3 circuit (pink) was bad. I have the original owners manual but there is no key for what each fuse controls, other than turn/break lights. Does such a chart/key exist to identify the fuses in the panel? Thanks again Chris for all your help.

paul55 · 04-29-2012, 06:21 PM

Sorry Splitrock ....thank YOU for your help too.

Aage · 04-29-2012, 06:30 PM

Quote:

Originally Posted by paul55

Found my problem with a meter, All the fuses looked good but the number 3 circuit (pink) was bad. I have the original owners manual but there is no key for what each fuse controls, other than turn/break lights. Does such a chart/key exist to identify the fuses in the panel? Thanks again Chris for all your help.

I can't say if a 1980 Owner's Manual has the same thing, but in my '74 Service Manual, there are electrical wiring diagrams of all the 1974 models, and the coloured wires are clearly laid out going to all the appliances and devices.

In other words, AS wiring diagrams of the '70s showed the items on the coloured lines. Do you not have a wiring diagram for yours in the owner's manual?