How to troubleshoot electronic board on WH?

[Kayteg1]

Suddenly this morning DW went to take hot shower and the water was only warm, what is from yesterdays sun.
It is Suburban WH and shows red light on control panel all the time. I bypassed thermo switches for no change.
Removed Circuit Board #06-235658-001 and what next?
Don't see anything burned, so is replacing the board my only way to figure out if it is bad?

[Gjac]

Is it a potted board where you can't see components or a newer board where the soldered components can be seen? Atwood has some simple checks with a multi meter to check the board I would think Suburban has something similar. Also do you have 12v coming into the WH? 12v coming out of the board to the Tstat? Sometimes plug to board get dirty cleaning contacts has worked for me in the past as well as cleaning grounds especially the one on the gas valve that is difficult to see. Also check the thermal fuse I have replaced two that have gone bad.

[Kayteg1]

In my case I had red light coming immediately after turning the switch on, meaning the board did not even try the spark. I clamp loose ignitor connector, that melted some insulation anyway.
As mentioned, beside big dealership who might have testing board, there is not much owner can do, than buy another board.
Beside, Dino boards are universal and likely will work for your fridge as well.
Not a bad thing to have spare.

[SCVJeff]

Is this pilot or spark start?

This happened to me on an Atwood the day before Quartzsite a few years ago and like an idiot I ran over to the local RV parts house and bought a Dino board without even looking. Now that the pressure was off I came back removed the burner and all brackets attaching it to the frame and burnished everything from the electrode, burner, flue, everything that's got a screw, back to the WH frame itself where the OEM controller gets ground when it's monitoring flame presence. The problem was corrosion that couldn't be seen (that's a flame On confirmation path) and any rise in resistance to ground from the burner will cause it to fail. I still have an unopened Dino board

[Kayteg1]

ScottG wrote:
Bigger dealerships with a parts dept. have a tester they can plug the board into to test it.

And charge me for testing probably more than $70 new board cost.
I will stop at the family in a week and that is where new board goes.
So far we open water form WH in the afternoon, to fill it up with the 120F water in the supply hose.

[ScottG]

Bigger dealerships with a parts dept. have a tester they can plug the board into to test it.

[Kayteg1]

Dig in the camper cabinets and PO left whole suitcase of manuals.
Here is WH wiring.
Looks that any light on control panel confirms the thermostats are good. Rest is the circuit board.
BTW high-limit has reset button what is black rubber on black cover = hard to see. I took cover off to notice it.


Click For Full-Size Image.

[Joe_Way]

Kayteg1 wrote:
...I already ordered new Dinosaur board, but will be really p***d when it turns something else.

You'll be Dino-Sore?

[Kayteg1]

As I mentioned, I bypassed thermostats to no change.
The red light comes on instant, meaning the board is not doing anything. Also after taking the cover off, I see LED on the board, that does not lights when I turn the main switch on.
I already ordered new Dinosaur board, but will be really p***d when it turns something else.

[Old-Biscuit]

Start by tracing the DC path.

RED (Fault) Light ON means it 'failed' to light off main flame & PROVE it lit

With ON/OFF Switch ON you should have DC from switch to the t-stats
From t-stats to module
Then from module to gas valve and spark electrode (DC on gas valve for 6-8 seconds WHILE spark electrode is firing CLICK CLICK CLICK)

If water temp is hot (130*F) normal t-stat (bottom one)will be OPEN...no DC to module
Normal t-stat closes when temp goes below 100*F so NO DC to module until water cools off/t-stat closes

Main flame (gas valve solenoids get DC) lights off ----milliamp signal is generated that must go back to module to keep DC on gas valve until t-stat opens

SO do you have DC to/thru the set of t-stats?
Does the spark electrode fire....gas valve solenoids get energized?

Trace the DC..THEN replace/fix vs trowing parts at it

Simple DC Test light can be used to trace DC.
Voltmeter better cause you can measure actual DC Voltage

Issue could be dirty connections, bad spark electrode, bad ground(s), bad module

[Kayteg1]

It is propane WH only.

[SCClockDr]

Was it on electric?
Was it on gas?
Do both fail?
Is there an outside shower?
Is there a temprature mixing valve?