Water heater T1661

Heatherdmc · 10-01-2023, 07:43 AM

All is great with a t-1661 sunline.except the hot water tank needs replaced. Any suggestions? Trying to find how big the tank is also.

**JohnB** · 10-01-2023, 11:24 PM

Can you give us your existing water heater's make and model number? See the sticker on the outside behind the drop-down door on the right facing it. And the year of your T-1661?

Sunline installed Atwood water heaters, and most were 6 gallons. But, if you are looking at a new tank, you have to get the right tank replacement; Atwood had many different tanks pending the model it was.

Pictures of the heater with the door down outside help, too. Especially if the sticker with the model number is faded beyond readable.

I hope this helps.

John

Heatherdmc · 10-02-2023, 01:42 AM

We bought an 85 anniversary addition. Pulled the heater yesterday. Pin holes like cheese. We actuarially are thinking of going thankless. But it won't be this season. Just buying the camper we will take it out one a maiden voyage but then be winterizing it.

**JohnB** · 10-02-2023, 06:55 AM

Quote:

Originally Posted by Heatherdmc

We bought an 85 anniversary addition. Pulled the heater yesterday. Pin holes like cheese. We actuarially are thinking of going thankless. But it won't be this season. Just buying the camper we will take it out one a maiden voyage but then be winterizing it.

Hi, I think you have a typo on the 85th-anniversary edition. Are you sure it is 85th? Sunline was not in business for 85 years. If you know the camper model year, that helps better.

They started selling tank kits again. There was a dry spell during early Covid, and you could not find a new tank almost anywhere. I'm making an "assumption" not knowing what you have; your older camper has the all-gas-only system. The gas valve runs the entire show, and no electricity is going to it. But, you may have a replacement in it also, and it has some level of electrical control.

And, pending the condition of the gas valve, etc., a whole new tank-type heater may be a better option than just buying a new tank kit. Dometic, who bought out Atwood, makes a tank type that will fit in the hole in the side of the camper. See this post for what it looks like installed in a Sunline. https://www.sunlineclub.com/forums/f...avy-20522.html

Going tankless, if you plan on going off-grid, (boondocking) or not on full hookups, let's talk about what you give up when going tankless. There are those who love their tankless heater and others who do not. It all depends on what style of camping you do.

Have a good campout!

John

Heatherdmc · 10-02-2023, 07:06 AM

Lol it's a 1985! ��

Casey1 · 10-03-2023, 06:32 AM

Hot water heater anod rods- Can't seem to find one that fits in right. They only turn in 1 thread or 2. Could these be metric? Thanks

**JohnB** · 10-03-2023, 06:52 AM

Quote:

Originally Posted by Casey1

Hot water heater anod rods- Can't seem to find one that fits in right. They only turn in 1 thread or 2. Could these be metric? Thanks

Hi Casey,

If your 2007 has the Atwood water heater installed (Sunline original), the aluminum tank does not require an anode rod, or does Atwood recommend adding one.

If you try using an anode rod in an aluminum tank, sooner or later, the odds are against you, as you can cross-thread the aluminum tank threads over time just draining the tank.

The tank is 1/2" NPT thread but can be very tight. They use a nylon drain plug so that if you cross thread when installing, you damage the plug, not the tank.

If your camper has been changed to a Suburban brand heater, they are steel tanks, which need the anode rod.

Hope this helps

John

Banjoman · 06-27-2024, 11:50 AM

Last summer I noticed a few drops of water dripping from my 1982 Sulnline 16 1/2. It was under the water heater so I went inside to look and sure enough it was wet in the water heater compartment. I removed it and found pinhole leaks on the bottom, of the aluminum tank. My first thought was to simply replace the tank but found that Atwood was out of business and the tanks were extremely hard to find. I did find one place that claimed to have one but the price was about the same as an entirely new unit.

I found an extensive article by JohnB on replacing these old Atwood heaters with a Dometic so I decided to go that route. I mean, how hard could it be to just swap one unit for another? Well, I found out it isn't so easy, at least for my case.

I found the Dometic heater on Amazon for a reasonable price (they really do sell everything). The job also requires filler side panels because the Dometic isn't as wide as the Atwood, a new door, and the electrical switch. The old gas only Atwood was the kind that's lit with a match from the outside, whereas the Dometic is lit electrically from the inside. I also got the sealing tape for around the edges, electrical wire, and a roll of tubing for the water line.

My first task was to address the floor that had rotted out under the leak. Peeling back the linoleum allowed me to dig out all the damaged floor material leaving a hole about the size of a cantaloupe above the metal sheeting underneath, but now I needed to figure out how to patch it. After some thought I got some wood pellets for a pellet stove and filled the hole. Then I poured polyester resin a little at a time letting it set before adding more until the hole was filled.

The next step was to frame the opening because the Dometic is not as wide as the Atwood. Inserting the new heater required a lot of trimming of the opening but it finally went in. Before installing however, I added additional lengths of wire to those on the heater so I could connect to 12 volts and to a switch. Next was to install the side filler panels and the door. The photo shows the installed unit.

The propane hookup was next and was a real pain. The copper propane tubing in the camper is of the hard kind that doesn't want to bend easily and when I tried to maneuver it to the new heater it collapsed and broke off and floor level. At this point I almost gave up and began thinking of selling the camper for cheap, but finally gave it another try. The pipe cannot be accessed from below due to the sheet metal underneath, so the only way was to cut out a circle of the linoleum and dig out an area around the pipe until I could cut it off cleanly and attach an adapter. Next I set off to Home Dopot for new tubing. The new is of a softer copper and bends easily by hand. At last the propane line was done.

The next task is to hook up the water lines. My old heater had multiple valves that allowed the heater to be bypassed so winterizing doesn't fill the tank with 6 gallons of antifreeze. However after many hours of lying on my side working through a small door on this job, my ribs couldn't take any more so I did not install any bypass capability. To see how it should be done read JohnB's article, and to see how I did it see the attached photo.

When it was all done with the propane turned on and the heater tank filled, I gritted my teeth and attached the wires to the switch. Nothing happened. Now I really wanted to set fire to the whole thing so I angrily turned the switch to off and to my amazement it came on. I was so careful about labeling the wires but some how I got them backward. The obvious fix of course would be to switch wires but as I was tired of working on this thing I took a marker and labeled the off to on and on to off.

So, now how can this camper be winterized without using gallons of antifreeze, one might ask. Actually quite easy as this is a very tiny camper with very little in the way of water lines. The process which was successful last winter, and I live in the northeast, is pretty simple. First shut off the pump and open all faucets. Then drain the fresh water tank, the water heater, the toilet and the shower hose, and then blow out the lines with compressed air. The lines from the heater area to the kitchen sink are the lowest in the system and are equipped with drain valves. This coming winter after doing the same, I will pump antifreeze until it just enters the heater tank (the lines are translucent) and shut it off. Then put some in the sink drains to fill the traps.

So that's it.

**JohnB** · 06-30-2024, 10:26 PM

Banjoman,

Thanks for sharing your saga/story. Your humor was good to keep you motivated through all this.

And for us to read!

Yes, the words "drop in and run", do not come to mind in this case. The piping on the back is a challenge. But, as you did, everything can be overcome in time with lots of thought and patience. You did well and have a working heater once again.

Keeping an eye on the piping connections for drips is my only thoughts on your good handy work. The newer style heater seems to lose the air pocket in the top of the heater more easily than the prior generation tanks. That air pocket helps with the thermal expansion of the water as it expands into the pocket. When the air pocket dissolves, the pressure can rise up to 150 psi, and the safety relief can weep to relieve the excess pressure. The water piping will see that 150 psi until a faucet, toilet, etc., is opened or the heater cools down, and the water expansion goes back down.

If your hose clamp setup allows a drip over time, they sell an adapter fitting from polybutylene piping (your gray piping) to PEX. Once into PEX fitting, you can use Flair-it swivel fittings on the ends of the male pipe of the water heater connections.

Happy camping this summer.

John

Banjoman · 07-04-2024, 12:00 PM

I probably should have mentioned in my previous post that prior to my decision to replace the leaking Atwood water heater with the Dometic, I tried to repair it. The leaks came from several tiny holes and since the tank is aluminum I tried to fix it with aluminum solder. And, it might have worked if I hadn't made one bonehead mistake. Aluminum solder can be applied with a MAPP gas torch so after buying the solder sticks I bought the torch. I cleaned the area around the holes and began to apply the solder over the damaged area. I got a nice layer of molten aluminum solder over the area with the leaks and was about to declare victory until my impatience ruined it all. To hasten cooling I hit it with compressed air. But instead of cooling as I had hoped, a hole bigger than a golf ball appeared. I hadn't counted on the heat melting the tank as well as the solder. Then of course the tank was completely ruined and my only path at that point was to go with the new Dometic heater.

**JohnB** · 07-05-2024, 07:41 AM

Hi Banjo,

Don't beat yourself up tool bad on the molten aluminum repair attempt. Aluminum has its own repair tricks different from those of carbon steel, copper, or other metals. I also did the oops a long time ago. The heat gets to the point where the metal melts apart instantly. Live and learn; if you are not trying, you are not learning. You always remember the real, oops moments. And they make great campfire stories.

John