Water Heater Ignition Problem

[HawkeyeJones]

If the components of the valve are fused that tight. REPLACE IT.
But first. if you are talking a solenoid valve get either a test light and hook across it wile your parnter turns on the gas switch.. Watch for the light while the sparker starts sparking (Should be on) if it's not on (make sure light works first by the way) then the valve might not be the problem.

OR a Common license plate light socket (Two leads) and a dash indicator lamp (Blace type to fit socket) and wire it across the solenoid. LIGHT ON = Good control board bad valve. Light off = Bad board.

I'm afraid I don't know what any of this means. Wiring a test light or a dash indicator lamp across a solenoid is all advanced training that I don't have. Regardless, I don't know where a solenoid would be or if I'd be able to access it with the valve connections fused the way they are.

One common reason for failure to detect the flame is corrosion on the igniter/sensor wire where it connects to the circuit board. The ignition pulse is powerful and gets past corrosion, but the sense signal is weak and gets stopped if there is corrosion there.Clean the connection with a pencil eraser.

I'll try this pencil eraser fix. I'm not confident that I'll be able to correctly identify the igniter/sensor wire, but I'll try a couple places.

Clean the gas tube to the burner. Blow some low pressure compressed air into the tube. Spider and other insects love to nest in that tube and it disrupts the gas flow.

Already done. There wasn't a significant blockage. Situation remains the same.

There is an easy way to check for propane while the ignitor is sparking. Just get one of the butane lighters for a barbeque and get it burning, hold it just below area of the spark and have someone turn on the water heater for you. If there is propane you will see it light, even if it turns off again when sparking stops. I have used that method of testing many times.

If there is propane flow over the spark, why wouldn't the spark ignite it? What would the butane lighter add to this equation?

 

[Mark_K5LXP]

Under $10 from most any purveyor of fine chinese merchandise. Handy gadget to have as part of any RV tool kit.

Solenoid valves turn on and gas flows when 12V is applied to them. No 12V, no propane. A test light connected to the solenoid wires right at the solenoid will show if 12V is present or not. From there it can be further isolated to 12V power, logic board, ground or gas supply.

If there is propane flow over the spark, why wouldn't the spark ignite it? What would the butane lighter add to this equation?

A known good ignition source. I haven't seen this on a water heater but have fixed it a few times on other spark ignited equipment where the high tension wire degraded and it was sparking somewhere other than the inside of the combustion chamber. So technically the logic board/spark circuit is working [tick-tick-tick-tick] but not sufficiently making it to the end point. Having a flame going when the propane solenoid opens up conclusively proves gas flow or not.

Mark B.
Albuquerque, NM

 

[pheasant16]

Same issue a couple years ago. A new board and igniter for good measure and was back in hot water. (Not from Gramma this time)

 

[NY_Dutch]

I expect this above your technical proficiency, but if you have an easily accessed Atwood furnace, the ignitor board can be used as a temporary substitute for the water heater ignitor board. If the heater works properly with the substitute board, you'll know what needs replacing. Just be aware that the furnace board will have a ~20 second delay before the ignition sequence begins after the switch is turned on.

 

[Kirk]

If there is propane flow over the spark, why wouldn't the spark ignite it? What would the butane lighter add to this equation?

I have troubleshot and repaired a lot of RV water heaters but it's up to you. Go back and look at post #4 again. You responded to Gary that you don't know where the igniter wire is but there is a picture of that igniter with the wire. There are many reasons why the propane might be available and yet not igniting. Have you actually seen the spark? Do you know that the igniter is adjusted into the proper position? If you want us to help you, you need to do some of the things that we ask. Both Gary and I have many years of RV experience, both come from electronic service careers, and both of us have repaired numerous Atwood water heaters. In fact, we lived all of the time and traveled in a motorhome that had the same exact water heater that you have. I owned that motorhome for 14 years and repaired that waster heater on several occasions.

None of us can help you if you are not willing to do the things we ask to troubleshoot.