Need Help With Perplexing Problem

[dagoose]

Ok, so I just bought a new (to me) 2004 Cedar Creek Silverback 33L BHTS. The first night I spent in it I turned on the Suburban SW6D (or SW6DE) water heater and it fired right up. The next morning it had quit working. I would turn the switch on and the switch would light but the small light that indicated that the heater lighted would not come on. I had a friend bring a voltage tester and it didn’t look like any juice was getting to the gas valve terminals. We figured it must be a bad Module. So I switched it to electric to have hot water. The electric worked fine at first (the previous owner replaced the element less than a year ago.) but after a day it quit working too (the breaker was fine).

So about a week later I went back to the camper with a new Module. I decided to try it once more before I installed it and it fired right up. It worked fine Friday evening and Saturday morning but by Saturday afternoon it quit working again. So I installed the new Module, tried it and again nothing happened. Once again the switch lighted up but the little indicator light did not light up. But when closing up the camper on Sunday I tried it once more and again it fired right up!!

I’m now thinking about replacing the gas valve assembly but since I have a couple of weeks before I’ll be out there again I thought I’d toss it out to you guys before I spend the money. So…..

1) Is there anything you can think of that I’m overlooking that would cause it to stop working intermittingly?
2) Is there a switch or anything to check between the fuse block and module?
3) Could there be a connection between the gas and electric BOTH not working? Are they tied together anywhere?

Thanks in advance for your help on this.

[nomad297]

You do know that the red indicator is not supposed to stay lit unless there is a problem with the water heater burner not firing, right? It should come on at first, then turn off once the burner is on.

Bruce

[dagoose]

Originally Posted by nomad297

You do know that the red indicator is not supposed to stay lit unless there is a problem with the water heater burner not firing, right? It should come on at first, then turn off once the burner is on.

Bruce

Yes I do. But the little light is not lighting at all except for the times the water heater fired up. But the water heater switch is lighting fine when turned on.

[wmtire]

See if maybe this FAQ we keep on the operation and understanding of how the Suburban water heater works may help you. I think there are a few things that need clarification.

http://www.forestriverforums.com/for...tml#post327988

If for some reason you may have unknowingly had the electric on at the same time as the propane, then the propanes thermostat would not call for heat, thus no need for the propane to come on.

The electric and propane operate individually of one another, each with it's own separate thermostat.

You may also want to check your bypass valves (also explained in the link) to make sure you are not just getting cold water mixed in with the hot water.

[bubbles]

The light may not come on again once the initial start sequence has ended. Only periodically it may come on if there is a slow start but that rarely happens. If the heater is functioning correctly the light will not come on again when the thermostat calls for igniting the burner to heat the water.

[Bama Rambler]

My question would be: Did you have hot water during the time that you think the heater wasn't heating?

My 'DSI Fault' almost never comes on. The only time I remember seeing it come on is right after running out of propane and refilling the cylinders.

[jeff64]

Have you googled troubleshooting suburban water heaters or checked out a you tube video?
On mine, the tech said that the red indicator shows that the DSI is enabled and firing, like nomad 297 said. I did experience, this weekend a hard start on propane and a hellofa bang once it lit on occasions which led me to do some "investigating" once I got back yesterday. There wasn"t anything in the gas tube( like spider nests), blew out the orifice with air, blew out the scale in the burner/ heat exchanger chamber with compressed air. When it backfired, it would blow a bunch of chunks into the door area. Took a brass tooth brush to the igniter electrodes and anywhere that could have been considered a ground path for the igniter ( ie. attachment points for electrodes) It seemed to light quicker, only time will tell

[dagoose]

Clarification. The water heater water is cold, I turn the switch on and the switch light comes on but the DSI light does not.

But then at a later time when I try it again the DSI light DOES come on and then goes out like it normally should and the water heater is functioning normally. The water gets hot.

So sometimes the DSI lights up and the heater lights and sometimes the DSI light does NOT come on at all and the water heater fails to light. In each instance the water is cold to begin with and the propane tank is full. And my water heater bypass valves are in the correct position.

So the problem is sporadic and not all of the time. So something electrical seems to be failing occasionally. If it was all of the time I might be able to figure it out.

It should also be noted that neither of my resets are tripped.

Thanks for the great replies so far.

[ov845]

Originally Posted by dagoose

Clarification. The water heater water is cold, I turn the switch on and the switch light comes on but the DSI light does not.

But then at a later time when I try it again the DSI light DOES come on and then goes out like it normally should and the water heater is functioning normally. The water gets hot.

So sometimes the DSI lights up and the heater lights and sometimes the DSI light does NOT come on at all and the water heater fails to light. In each instance the water is cold to begin with and the propane tank is full. And my water heater bypass valves are in the correct position.

So the problem is sporadic and not all of the time. So something electrical seems to be failing occasionally. If it was all of the time I might be able to figure it out.

It should also be noted that neither of my resets are tripped.

Thanks for the great replies so far.

Please don't get offended, but how long do you let the hot water run? Having the heater bypass in the wrong position can cause the symptoms you're describing. If it's not too much trouble could you post a picture of the bypass valves? Just to have a fresh set of eyes looking at it.


Happy Camping!

2012 Ram 1500 Crew Cab 5'7" Bed
4 X 4 Engine 5.7L Hemi Gear 3.92
Airlift 1000
2015 2809W Windjammer (Diamond Package)
Husky Centerline WDH

[dagoose]

Originally Posted by ov845

Please don't get offended, but how long do you let the hot water run? Having the heater bypass in the wrong position can cause the symptoms you're describing. If it's not too much trouble could you post a picture of the bypass valves? Just to have a fresh set of eyes looking at it.


Happy Camping!

2012 Ram 1500 Crew Cab 5'7" Bed
4 X 4 Engine 5.7L Hemi Gear 3.92
Airlift 1000
2015 2809W Windjammer (Diamond Package)
Husky Centerline WDH

I'm not at the camper so I don't have any pictures I can post. But I can say that the bypass valves are in the correct position. And even if they weren't would that prevent the water heater from lighting? On a cold start I turn on the switch for the propane operation, the switch lights up, the DSI light does NOT and the water heater won't light off.

[contourcrazy]

Does anything else propane work on the coach?

[Bama Rambler]

Let me see if I have this right?

You're having problems with both gas and electric sides of the heater?
You've replaced the control module and it worked intermittently?
It's only worked on electric once for a little while?
Both Hi-limits are not tripped?


The gas and electric sides on that heater are completely separate except for being in the same compartment. Even the thermostats and hi-limits are separate for each side.

I think you need to start it and let it run till it stops, and then start checking for voltage along the circuit until you find where it stops.

[dagoose]

Originally Posted by contourcrazy

Does anything else propane work on the coach?

The stove works good but the furnace does not. But I think that may be another issue.

[dagoose]

Originally Posted by Bama Rambler

Let me see if I have this right?

You're having problems with both gas and electric sides of the heater?
You've replaced the control module and it worked intermittently?
It's only worked on electric once for a little while?
Both Hi-limits are not tripped?


The gas and electric sides on that heater are completely separate except for being in the same compartment. Even the thermostats and hi-limits are separate for each side.

I think you need to start it and let it run till it stops, and then start checking for voltage along the circuit until you find where it stops.

It was working intermittingly even before I replaced module. And the electric worked at first and then stopped (the heater was full of water from the get-go). High limits are not tripped. But those high limits are right together in the same piece, aren't they? That may be a good place to start looking.

[Harkerr]

It is possible tha you have an intermittant power problem to the igniter module. Check all connections.

[SweetOleBill]

I totally agree on check all connections. It seems like a loose or corroded connector.

[dagoose]

Sounds like good advice. I'll be doing that this weekend.

[awellis3]

Originally Posted by dagoose

Could there be a connection between the gas and electric BOTH not working? Are they tied together anywhere?

Ten years as an auto mechanic taught me that an electrical problem such as yours is often caused by the grounding circuit. It is common to both sides of the system and if loose or corroded can cause the problems you are having.

[satdog01]

I am confused on the switch light that comes on when trying to use propane. When using propane, the DSl light should come on and go out after a few seconds and stay off until the switch is turned off. I had a bad control board and the DSL light never went out when the propane switch was turned on. The other light is for the electric only. If you are not getting warm water after 20 minutes or so there is an electric issue. Also not mentioned here, check the outside electrical switch on the the tank, it must be on as well. Look at it close, it is backwards IMHO in that it should be off when it is on.

[Kevin & Judy]

Had the same problem, Found it was the switch in the master panel where you turn it on and off. .. Replaced the switch and have had no problems since.