Suburban water heater problem

[tjohnsen]

I have a 2005 Keystone Raptor 299MP with a Suburban SW12DE water heater. It has run well on propane until recently. I run it exclusively on LP because it hasn't wanted to work on electric, but we boon dock a lot anyway so I didn't worry about the electric element issue.

About two months ago we had family over and they stayed in the trailer. We could not get the water hot. Weird thing is that the LP is cooking good and hard under the heater like it is supposed to. Good blue, strong flame with the audible rumble I've always heard when the water is heating.

I looked for answers and this is what I've done:

- Made sure the valves were closed at the exterior shower
- Made sure the tank is full. I get strong water flow out of all hot faucets in the trailer. Water gets almost luke warm so I know water is coming out of heater
- I heard it could be the bypass valve. I've never used the bypass valve because it rarely gets below freezing here. However, I did find one valve (couldn't find two) coming off the cold side of the bottom of the back of the heater. I turned the valve and it feels good. I've felt failed gate/ball valves before where there is not resistance when turning the valve. This one has a good amount of resistance to it as though it is working fine.

I replaced the anode and flushed the tank two years ago, perhaps I need to do that again.

Can anyone point me in a direction to start in fixing this thing?

Thank you!

[tjohnsen]

I ordered a new annodoe rod and the thin socket to get my electric element out. The items will be here by this weekend so I'll open it up then and post up my results.

Thanks again.

[WA4HTZ]

Were any faucets turned on in the trailer during the 30 min. you were running the burner? If not, then there shouldn't have been any flow in or out of the heater. It seems like it would be just like heating a pot of water on a stove. The water in the heater should stay in the heater, I would think. Is your water exceptionally cold and it just takes longer than 30 min. to heat 12 gal.? Just grabbing at straws here 'cause this is a real head-scratcher! Please let us know if you find out what is happening.

Ken

[Old-Biscuit]

tjohnsen wrote:
Ok great info everyone thank you. I'll address the electric element after I get the LP working again.

Doug, I did what you said right off the bat. I let the water heater flame go for about 30 minutes...I don't know if it would ever shut off right now. After that I pulled the pressure relief valve and got that very mild luke warm water same as at the faucets.

OB thanks for the photos. That gives me something to work off of when I get home!

YOU stated:
30 minutes of propane ON
Opened T&P Relief Valve via lever and got 'Mild Luke Warm Water'

30 minutes should have been enough time to heat the water.....t-stat is set for 130*F
(Should let it operate until it shuts down by it's self. Then check water out of T&P Relief Valve)

But mild luke warm water out of T&P Relief Valve after 30 minutes.
Suspect cold inlet dip tube has blown off.
Cold mixing with hot inside tank

SW12-DE uses a 12,000 btu/hr burner....



IF water was HOT in WH Tank THEN I would be checking showers/bypass valving.
Especially since you said 'Family' had used RV...no hot water

[tjohnsen]

Ok Doug I will double check this. But the outside shower is like the valve on the water heater. In the 10 years I've owned the trailer I've never used it. I'll recheck everything though.

[dougrainer]

Even tho in 37 years as an RV Tech, I have NEVER seen this. But, there are people that swear this happens. IF your outside shower hot and cold valves are ON and you have the faucet head shut OFF, then you will get your problem,---luke warm water at the faucets. Check all your faucets and make sure they are OFF. Doug

[tjohnsen]

Ok great info everyone thank you. I'll address the electric element after I get the LP working again.

Doug, I did what you said right off the bat. I let the water heater flame go for about 30 minutes...I don't know if it would ever shut off right now. After that I pulled the pressure relief valve and got that very mild luke warm water same as at the faucets.

OB thanks for the photos. That gives me something to work off of when I get home!

[Old-Biscuit]

donn0128 wrote:
There are three things the WH needs to work on electricity.
120VAC, continuity thru the temp sensor pack and a good heating element.
Open the WH outside door. Down near the bottom left you will see a small switch. Turn it on. Next, above the switch is a square rubber cover, about 4 inches square. There you will see a couple of what look like buttons. The LH side one is the reset for 12VDC. The RH side one is 120VAC reset. Push it in. Before you try this, be sure you have water flow. Wait 20 minutes and see if you have warm water. No hot water? Then you need to check the heating element, it is quite possible you have burned it out one time or another because you connected to shore power with no water in the tank. It only takes one time and no more than a minute to kill the electric element.

"Push To Reset"
That is for the HIGH Temp T-stat
If tripped NO heating function will occur

LEFT SIDE---that is for 120VAC electric (Black wire)

RIGHT SIDE--that is for 12V DC propane (Red wire)

IF tripped you will 'feel' them reset when pushed
If 'connector wire' between high temp (top) and normal temp (bottom t-stats then NO current flow ---no heat function
120V AC wire burnt thru in this pic



Electric element.
Under cover below/behind gas valve
Test with 120V AC CB OPEN
*NO Continuity between black wire terminal and white wire terminal---bad element
*Continuity between white wire terminal and element flange...shorted element

1 1/2" thin wall 6 point socket to R&R



Propane.
From your post ------"Good blue, strong flame with the audible rumble I've always heard when the water is heating.

So the propane flame is lighting and heating ---just luke warm water flows from faucets

That is result of cold mixing with hot
IF BOTH inside & outside showers are turned off at cold/hot knobs (not just with shower handle lever/button) then the ONLY place for cold/hot to mix is at that 'COLD INLET/BYPASS' valve.

Valve NOT set to 'normal' (cold inlet position) OR valve leaks thru
This pic is a one valve system....valve handle set to 'Bypass Position' (no flow into WH)
Normal Position..turn handle so it is parallel with cold water line



Rare chance -----
IF cold inlet DIP Tube has come off then instead of cold water being directed towards 'bottom' of tank as HOT is used the cold would spray into tank undirected, diluting hot water section -----warm water.

Remove anode rod, drain/flush tank then using a bright flashlight look inside for a plastic tube laying on bottom
Easier to see if electric element removed.

[MFL]

dougrainer wrote:
Remember, IF you have NOT turned any valves then that cannot be your problem. FIRST rule is to Open the Pop Off valve after the flame has shut off. IF you get HOT water, then you know the water heater is not your problem. You then check the backside valves and your plumbing. Doug

Agree with Doug. Also if it's been 2 years since checking anode/flushing heater, I would do it soon.

Jerry

[dougrainer]

Remember, IF you have NOT turned any valves then that cannot be your problem. FIRST rule is to Open the Pop Off valve after the flame has shut off. IF you get HOT water, then you know the water heater is not your problem. You then check the backside valves and your plumbing. Doug

[donn0128]

There are three things the WH needs to work on electricity.
120VAC, continuity thru the temp sensor pack and a good heating element.
Open the WH outside door. Down near the bottom left you will see a small switch. Turn it on. Next, above the switch is a square rubber cover, about 4 inches square. There you will see a couple of what look like buttons. The LH side one is the reset for 12VDC. The RH side one is 120VAC reset. Push it in. Before you try this, be sure you have water flow. Wait 20 minutes and see if you have warm water. No hot water? Then you need to check the heating element, it is quite possible you have burned it out one time or another because you connected to shore power with no water in the tank. It only takes one time and no more than a minute to kill the electric element.