Surburban SW6D 6.0 G Water heater turning off after 3 min

[Shelborne]

Hello everybody, I have a question about my water heater.

I have a 2007 Northwood Nash 17 C with a suburban SW6D 6 gallon water heater.

It has been acting extremely strange. I had problems with it last week, when I pressed the on button the light didn't come on, and nothing would happen. Then, it came on sporadically but then shut off and wouldn't come back on.

Yesterday, it turned on and then off after about 3 minutes, and today it did the same. Last night I was frustrated, so I went to bed, and then turned it on when I got up, and the red light came on and it ignited but went out again after about three minutes.

I have plenty of propane, and other appliances in my RV are working fine on propane.

When I press the on button now in the RV, nothing happens. There is no red light, nothing clicks.... etc... it just seems dead.

I have checked for loose wires, but everything looks fine. No rust anywhere that I can see. Everything looks great.

Water tank is full and cold water is coming out of all hot water taps.

I have checked the reset buttons, and nothing is tripped. I have checked all fuses.


When I open the relief valve a little bit of hot air comes out, but that's it. It doesn't stay lit long enough to begin sweating on the outside.

I repaced the igniter last week after this started happened but it doesn't look like it solved the problem I was having.

Does anybody have any suggestions?

I'm still dealing with the refrigerator issue, so I have packed ice on this trip. These occurances are wearing me out.

Although the coach is a 2007, it's probably only been used a total of seven times, and I bought the unit new. It has sat for 6 years and I bought it in 2008.

THANK YOU! Any help would be greatly appreciated!

[Shelborne]

Thank you Wildtoad for the information.. Those are simple and easy checks that I will definitely use'

[Shelborne]

Hello Doug!

Well, that seems to have been the issue, the hot water tank was bypassed. This doesn't make a lot of sense, because I drained all of the water earlier and then refilled the tanks yesterday..... then checked the water tank and it had water in it... so, I just assumed everything was normal. I haven't used the trailer really in 6 years, so it appears I have some catching up to do, and need to become more familiar with it..

Thank you very much for your input, and solution!

[Shelborne]

Thank you Doug! The hot water heater tank bypass valve is located under pull out bed my daughter is sleeping on right now, and I'm going to check it as soon as she gets up. It was a late night last night.

I took pictures of how the valves are supposed to be during operation and when I winterize them, but between using this trailer and working with my fathers trailer, perhaps I got something backwards. I sure hope that is the case!

I even labeled the valves so when I turned them they would say "summer..."bypass"... "drain"... etc.... It doesn't seem to have helped because they still drive me a bit nuts....turn a valve the wrong way and water or rv winterization fluid starts pouring out the two drain valves in the back end. I'm relatively mechanically intelligent (at least i tell myself this) haha, but definitely have made my share of mistakes.

I'll keep you posted!

[wildtoad]

Quit trying to heat the water until you find out why you are getting air from the relief valve, should not happen on a full water tank. An easy test is to, with pump off and NOT connected to city water, operate the relief valve to relieve any pressure, remove the anode rod and drain the tank ( clean it while you're at it ). With the rod out turn on the pump and open a hot water faucet. If you get water from the faucet your wh is in bypass mode. If it comes out of the wh drain then you have a problem! 😉

[dougrainer]

Shelborne wrote:
Thank you very much Autumn Snowbird!

When I open the relief valve on the outside, no water comes out. The water pump is full and it has stopped running, and when I turn on the hot water taps water comes out but it's just not hot water... Ice cold. The water heater has water in it, because I'm getting water out of my hot water taps. Also, I pulled the drain plug on the water heater, and water pours out of it.

I'll try the other suggestions that you have, but right now it's not igniting and the light's not even turning on. If it were a nest, it would seem like it wouldn't turn on at all, but it turned on last night... and this morning... it then shut off. Update: the burner tube is clean.

1. If you open the pop off valve and NO water comes out, your water heater is NOT full of water.
2. If you have water out of your inside faucet hot water valve, that does NOT mean you are pulling water from the Water Heater. You probably have the BYPASS valves set for winterization. When that happens water will still come out both hot and cold. The water that drained out was probably residual from previous use
3. Odds are the water heater has less than 1 or 2 gallons of water and the ECO is tripping causing the 3 minute shut off
4. You MUST have water coming out of the pop off valve. Period. Doug

[Shelborne]

Thank you very much Autumn Snowbird!

When I open the relief valve on the outside, no water comes out. The water pump is full and it has stopped running, and when I turn on the hot water taps water comes out but it's just not hot water... Ice cold. The water heater has water in it, because I'm getting water out of my hot water taps. Also, I pulled the drain plug on the water heater, and water pours out of it.

I'll try the other suggestions that you have, but right now it's not igniting and the light's not even turning on. If it were a nest, it would seem like it wouldn't turn on at all, but it turned on last night... and this morning... it then shut off. Update: the burner tube is clean.

[Artum_Snowbird]

Your tank should be filled to the brim, and only water should come out the relief valve. Put the water pump on until it stops, all taps closed. Open the relief valve. You should get water only.

You have had the unit for quite a few years, so you know about bypass valves and winterizing valves. Some units have a check valve on the outlet of the tank. It's only about 3/4 of an inch long. It could be frozen shut and your tank is not filling, but when you are off bypass and on tank, if you get water out of the hot tap it has to come through the tank.

Another option is an insect nest in the burner tube. Sometimes this ignites inside and will heat the fusible link and open it. Look for a wire with what looks like a fuse in front of the outlet of the burner tube. My fusible link had a corroded connection at one end and caused the heater to not start at all.