Rheem Performance water heater reset works again despite no vial change

[Shadly]

I have a Rheem Performace water heater. I came back from vacation, turned it on, and it shut down with a code right away. The code was a code 7 - Flammable Vapor Sensor. I reset it doing the 7 knob turns, and it works now, no issues. I did not change the glass vial or take any other course of action though, so, based on what I've read, I would think resetting alone would not work. But it did.

If I had a serious gas leak, wouldn't resetting it fail to correct the issue?

 

[Twowaxhack]

If the glass vial broke the heater wouldn’t burn but for just a few seconds. The pilot would work fine.

I’ve never heard of Rheem having a reset on a flammable vapor incident on the gas control. New one for me.

It must be a system that uses low voltage supplied by a wall outlet.

 

[Shadly]

This is all second hand. I'm not at the water heater's location; I am assuming they read the code correctly. It has been working correctly for about a day now. I would be surprised if they would design a water heater that could just be reset and run if there was a gas leak.

If the glass broke, there is no way it would work even with a reset, correct? Do some units use an alternative system to the glass vial?

 

[Twowaxhack]

If the glass vial breaks the burn chamber is closed off from combustion air.

There is a control on some Rheem tanks that will throw a fvi code, I wasn’t aware of it, I’ve never worked on one like that.

The Rheem units that I service just have the glass vial of peanut oil. It holds open a spring loaded door.

 

[Shadly]

OK, so the fact that the heater is working now means the vial must be intact. I'll have my father try to confirm this visually. Just so I understand what could have happened here, is there any other way a code 7 warning could have happened? Is there a secondary sensor that could lock out the heater? Is this something that can happen on startup if the heater has been unused for a long period of time?

The only theory I have is that there was some vapor build up from a sewage extractor located in the same room as the heater.

 

[Twowaxhack]

If the water heater is burning then the vial is intact.

I doubt you had a vapor incident, but maybe you did.

 

[Twowaxhack]

The vial only is useful if the water heater is burning the vapor and overheats the burn chamber.

The vial detects high burn chamber temperature. This causes the oil to expand and break the glass vial. This release a spring loaded door to shut the air supply off to the heater.

 

[Shadly]

Makes sense to me now, thanks.

 

[TomFOhio]

Shadly are you talking about the small sensor that screws to the tank with the two wires and the reset button in
the middle.

 

[Shadly]

No, I was referring to the TRD near the burner. If there is some other sensor that can cause a No. 7 code, I would love to know about it.

 

[Twowaxhack]

The TRD fir the Rheem water heaters I’ve repaired are strictly mechanical, no wires.

 

[GReynolds929]

Is it a power vent or atmospheric vent water heater?