What could be a problem with DSI Suburban hot water tank?

[Rock2]

It has been doing that every time when I turned it on. I cleaned tube, polished and adjusted electrode, No cracked on electrode, battery is in full charged and half empty propane tank and the other tank is full. It would ignite flame but shut off in every 6 seconds. So I switched to electric. Let it runs for ten min then I switched back to propane. It came back on without any problem. It does not make sense. Is it possible that circuit card is bad? Any advise would be great appreciate it.

[Chris_Bryant]

Rock2 wrote:

Chris Bryant wrote:
Keep in mind the current path for the flame sensing- it has to go through the spark wire and electrode, then through the burner, attachment to the case, etc. before getting back to the circuit board via its ground connection.
My take- make sure all of the burner mounting points are tight- I even run ground wires from the electrode mount back to the gas valve, or closest good grounding point.

I have thought about that run a ground wire from the electrode mount to the gas valve. What gauge of wire do you recommend?

It doesn't have to be much- the current for the flame sensing is ~15 microamps. I use whatever I have around- usually #14, but that's overkill, really.

[Rock2]

donn0128 wrote:
Bad or corroded terminals on the control board would be a start.

Glad you brought it up. I pulled the connector and reconnect few times. It is possible that terminals may develop film from humidity or whatever.

[Rock2]

Chris Bryant wrote:
Keep in mind the current path for the flame sensing- it has to go through the spark wire and electrode, then through the burner, attachment to the case, etc. before getting back to the circuit board via its ground connection.
My take- make sure all of the burner mounting points are tight- I even run ground wires from the electrode mount back to the gas valve, or closest good grounding point.

I have thought about that run a ground wire from the electrode mount to the gas valve. What gauge of wire do you recommend?

[Chris_Bryant]

Keep in mind the current path for the flame sensing- it has to go through the spark wire and electrode, then through the burner, attachment to the case, etc. before getting back to the circuit board via its ground connection.
My take- make sure all of the burner mounting points are tight- I even run ground wires from the electrode mount back to the gas valve, or closest good grounding point.

[Old-Biscuit]

Harvard wrote:
Could be one of the two gas valve solenoids coils going bad (failing open). The solenoid coils should be about 40 ohms each. They have known to be intermittent with temperature.

YEP.

2 typical issues that cause main flame to drop out

Spark electrode...used as flame proofer. Main flame has to engulf it and generate a milivolt signal back to circuit board for power to stay on gas solenoids holding them open.
Bad signal track------either connections on electrode/high tension wire, at circuit board or jumping to ground


OR

bad/weal gas solenoid.........typically inboard one cause water drips from T&P Relief vlave into inside one

[Harvard]

Could be one of the two gas valve solenoids coils going bad (failing open). The solenoid coils should be about 40 ohms each. They have known to be intermittent with temperature.

[donn0128]

Bad or corroded terminals on the control board would be a start.

[Sprink-Fitter]

Rock2 wrote:
but shut off in every 6 seconds.

What are you saying here?