water heater works fine - IF- I leave door open

[Timeking]

There are a lot of posts here about changing the control board, etc. But this has me stumped. Suburban SW6DEL.

If I leave the outside door closed, it will light, then go out, will not re-light, will not heat the water.

If I open the door, it will light, and heat the water up until hot then turn off (normal operation).

If I open the door, it will light, and run UNTIL I close the door, and it turns off.

WHAT?!?!?

[Boon_Docker]

Good it hear that you got it working.
I think that many of us have replaced things that didn't need to be replaced while trouble shooting a problem. 😉

[Timeking]

It turned out that it was the igniter/sensor (DSI electrode). Replaced and works as it should. $11. Of course I needless replaced the controller ($90 with cover).

And I stupidly thought while I was tearing things apart, might as well replace the switch ... which wouldn't come out, and wires too short, then wouldn't go back in. Just a tremendous pain for something that should have been easy, and in hindsight shoulda been left alone.

[doxiemom11]

Our friends have the same problem on their trailer. Even a brand new ( when they had to replace theirs) with all kinds of air mixture adjustment tries, just will not run with the door closed.

[dougrainer]

23hotrodr wrote:

dougrainer wrote:

23hotrodr wrote:

Timeking wrote:
"The RETURN millivolt signal for flame is NOT that strong and will be disrupted by a slight short to ground." Return signal? Are you saying that the Suburban design uses the spark apparatus as double duty for whether or not the flame lit? If true, that seems dumb.

There does not appear to be any damage to the orange wire, looks new. The connection to the lug is shiny and clean.

As suggested, I cleaned the burner tube. The air-gas mixture is fixed, not adjustable.

--- Are you positive the air mixture is not adjustable? On all RV WHs I've seen, there is a mixture adjustment where the burner tube meets the gas valve. You adjust it by loosening a small screw and twisting it on the tube to open or close the slots in it to add or block air.

Whenever I see a statement like this, I ask the question-----How long have you been working on RV Water heaters and/or RV's ? Because you are wrong. Doug

PS, I have seen a LOT more RV WH'ers than you(thousands):B

Thank you doug for putting me in my place. I have always appreciated the time you take and the expert advice you have given to help others over the years. I was simply trying to help by offering a small suggestion that might possibly have been overlooked. I in no way was trying to compete with you and your expertise. You are even more correct when you state you have seen 1,000s more WHs than I have since I am totally blind and have really never "seen" a single one. All I have done for many years is do virtually all the maintenance and repairs on my own MH and helped a few others find and fix problems with theirs. I have also had to repair things that the professional RV techs either screwed up or outright destroyed on my MH the few times I took it to them for repairs I thought were beyond my capabilities. I am extremely sorry for having tried to help with this issue, since I am obviously ignorant. I always look forward to hearing your advice to others and have learned from it numerous times. Best regards- Mick

Sorry, but it REALLY irks me when I see posts such as yours. I did not mean to sound so harsh. The reason is, "some" RVer's think PROfessional RV techs are just cheap oil changers. The RV's and appliances are constantly changing and what YOU think is absolute or standard is just not so. These same type people think if they have a very unusual problem of fix it is automatic that the poster has the exact same problem and fix. Case in point is Circuit boards on Water heaters/Furnaces/Refers/AC units. In the past 15 years, these type parts RARELY fail due to the constant analyzing of failures and updating the Boards to prevent future failures and problems. Dino Boards---Great product, needed 20 to 25 years ago, when they fixed the inherent defects in OEM boards. But, not needed now as the OEM boards have the failure problems of the past fixed and updated. Doug

[Timeking]

Now I am in the "throw parts at it until fixed" mode. I replaced the controller with a $78 Dinosaur. Same problem. So ... I took the cover off the thermostat/ECO compartment, and the problem went away!! Theory is that the ECO has become overly sensitive (?) and I ordered a new one $17 to replace the right-hand switch which controls the propane mode. All of which sorta makes sense in a kinda nonsensical way.

here is a good resource:
https://manuals.heartlandowners.org/manuals/Troubleshooting%20Guides%20and%20Tips/Water%20Heater%20Troubleshooting%20-%20Suburban%20V1.3.pdf

[Gdetrailer]

23hotrodr wrote:

dougrainer wrote:

23hotrodr wrote:

Timeking wrote:
"The RETURN millivolt signal for flame is NOT that strong and will be disrupted by a slight short to ground." Return signal? Are you saying that the Suburban design uses the spark apparatus as double duty for whether or not the flame lit? If true, that seems dumb.

There does not appear to be any damage to the orange wire, looks new. The connection to the lug is shiny and clean.

As suggested, I cleaned the burner tube. The air-gas mixture is fixed, not adjustable.

--- Are you positive the air mixture is not adjustable? On all RV WHs I've seen, there is a mixture adjustment where the burner tube meets the gas valve. You adjust it by loosening a small screw and twisting it on the tube to open or close the slots in it to add or block air.

Whenever I see a statement like this, I ask the question-----How long have you been working on RV Water heaters and/or RV's ? Because you are wrong. Doug

PS, I have seen a LOT more RV WH'ers than you(thousands):B

Thank you doug for putting me in my place. I have always appreciated the time you take and the expert advice you have given to help others over the years. I was simply trying to help by offering a small suggestion that might possibly have been overlooked. I in no way was trying to compete with you and your expertise. You are even more correct when you state you have seen 1,000s more WHs than I have since I am totally blind and have really never "seen" a single one. All I have done for many years is do virtually all the maintenance and repairs on my own MH and helped a few others find and fix problems with theirs. I have also had to repair things that the professional RV techs either screwed up or outright destroyed on my MH the few times I took it to them for repairs I thought were beyond my capabilities. I am extremely sorry for having tried to help with this issue, since I am obviously ignorant. I always look forward to hearing your advice to others and have learned from it numerous times. Best regards- Mick

Don't feel too bad, I had a much older pilot light Suburban from the 1980s, I do believe it did have a adjustable shutter..

But, dig some digging and found a photo of the newer DSI Suburbans and Doug is correct.



Found that photo HERE

So, there is no shutter to adjust, no way to compensate for altitudes other than changing the jet.

Stock is setup with a jet for 4500 ft elevation, anything higher than requires a new jet..

The OPs issue has to be boiling down to not correct fuel for the air which could be a partially blocked jet..

[23hotrodr]

dougrainer wrote:

23hotrodr wrote:

Timeking wrote:
"The RETURN millivolt signal for flame is NOT that strong and will be disrupted by a slight short to ground." Return signal? Are you saying that the Suburban design uses the spark apparatus as double duty for whether or not the flame lit? If true, that seems dumb.

There does not appear to be any damage to the orange wire, looks new. The connection to the lug is shiny and clean.

As suggested, I cleaned the burner tube. The air-gas mixture is fixed, not adjustable.

--- Are you positive the air mixture is not adjustable? On all RV WHs I've seen, there is a mixture adjustment where the burner tube meets the gas valve. You adjust it by loosening a small screw and twisting it on the tube to open or close the slots in it to add or block air.

Whenever I see a statement like this, I ask the question-----How long have you been working on RV Water heaters and/or RV's ? Because you are wrong. Doug

PS, I have seen a LOT more RV WH'ers than you(thousands):B

Thank you doug for putting me in my place. I have always appreciated the time you take and the expert advice you have given to help others over the years. I was simply trying to help by offering a small suggestion that might possibly have been overlooked. I in no way was trying to compete with you and your expertise. You are even more correct when you state you have seen 1,000s more WHs than I have since I am totally blind and have really never "seen" a single one. All I have done for many years is do virtually all the maintenance and repairs on my own MH and helped a few others find and fix problems with theirs. I have also had to repair things that the professional RV techs either screwed up or outright destroyed on my MH the few times I took it to them for repairs I thought were beyond my capabilities. I am extremely sorry for having tried to help with this issue, since I am obviously ignorant. I always look forward to hearing your advice to others and have learned from it numerous times. Best regards- Mick

[wa8yxm]

Suspects
The spark gap (often too wide)
The air/fuel mix (No not sure which way to adjust the damper)

[Old-Biscuit]

23hotrodr wrote:

Timeking wrote:
"The RETURN millivolt signal for flame is NOT that strong and will be disrupted by a slight short to ground." Return signal? Are you saying that the Suburban design uses the spark apparatus as double duty for whether or not the flame lit? If true, that seems dumb.

There does not appear to be any damage to the orange wire, looks new. The connection to the lug is shiny and clean.

As suggested, I cleaned the burner tube. The air-gas mixture is fixed, not adjustable.

--- Are you positive the air mixture is not adjustable? On all RV WHs I've seen, there is a mixture adjustment where the burner tube meets the gas valve. You adjust it by loosening a small screw and twisting it on the tube to open or close the slots in it to add or block air.

Guess all of your WHs were Atwoods
Suburban ,,,,which OP has....does not have ANY air shutter/air mixture adjustments
Suburban uses gas flow to pull correct air in via venturi affect

[dougrainer]

23hotrodr wrote:

Timeking wrote:
"The RETURN millivolt signal for flame is NOT that strong and will be disrupted by a slight short to ground." Return signal? Are you saying that the Suburban design uses the spark apparatus as double duty for whether or not the flame lit? If true, that seems dumb.

There does not appear to be any damage to the orange wire, looks new. The connection to the lug is shiny and clean.

As suggested, I cleaned the burner tube. The air-gas mixture is fixed, not adjustable.

--- Are you positive the air mixture is not adjustable? On all RV WHs I've seen, there is a mixture adjustment where the burner tube meets the gas valve. You adjust it by loosening a small screw and twisting it on the tube to open or close the slots in it to add or block air.

Whenever I see a statement like this, I ask the question-----How long have you been working on RV Water heaters and/or RV's ? Because you are wrong. Doug

PS, I have seen a LOT more RV WH'ers than you(thousands):B

[dougrainer]

There IS NO adjustment on this Suburban. Just make sure the burner tube is clean. A LONG shot for this problem could be the Burner flue tube has a Insect nest. The standard test for this is to roll a golf ball from the top exit and it should come out at the burner. Doug

[Gdetrailer]

Timeking wrote:
Wow. Learned something new, surprising at my age (72) and the fact I am a degreed chemist with 37 years experience in environmental science. Just when you think you know it all ... you don't!!!

There is nothing in the Suburban manual that suggests the air/gas mix can be altered, and it doesn't look like it is possible.

Air adjustment may not be very obvious but there should be an adjustable "shutter" near the gas valve and orifice on the burner side.

Found a video that should be helpful on finding and adjusting the shutter..

HERE

Of course, if your water heater has worked fine in the past with the door closed, something else may have changed to cause your current issue and I would be concerned that it has changed.

Typically a clogged orifice from dirt or spiders causes the most trouble with propane side of things so make sure you have cleaned the orifice and burner before making any air adjustments.

You are looking for a good all blue flame, any yellow color is incomplete burn which is typically improper air/fuel mix. But keep in mind the mix changes slightly when the door is closed.

[enblethen]

What is the exact model of the water heater? Tag should be on frame of the unit.

[Timeking]

Wow. Learned something new, surprising at my age (72) and the fact I am a degreed chemist with 37 years experience in environmental science. Just when you think you know it all ... you don't!!!

There is nothing in the Suburban manual that suggests the air/gas mix can be altered, and it doesn't look like it is possible.