Suburban Water Heater Wiring (propane)

[MtnGuy]

In doing a diagnostic wiring search for a "non-existent" propane problem (propane burner would not fire......water not cool enough......duh-uh ), I noticed the wire from the inside propane switch goes to the propane thermostat. The wiring diagram in manual shows that it should be connected to the hi-limit switch. Every thing has worked fine with this setup (now ), but could this cause me a problem in the future ??? Not a big deal to switch the wires, but if everything works why mess with it unless y'all think it might be a problem.

[Herk7769]

Chap, the high limit switch IS the propane thermostat.

Below 100 degrees it is closed (calling for heat) above 120 degrees it is open (removes power to solenoid valve).

[MtnGuy]

Lou, the 12 volt wire goes to a plain "device", then the fuse-able link goes to a "device" with a reset button on it. I presumed the 1st "device" is the thermostat, but not sure.

In the wiring diagram, it shows a hi-limit switch and a thermostat.

[Herk7769]

The photo below is of BOTH "devices" (One on the left is for the AC and the one on the right is for DC per the attached wiring diagrams).

The entire device is called the "Thermostat"

The top "button" is the high limit reset on the High Limit (120 degree) thermostat; then a fusable wire is connected to the Low Limit (100 degree) thermostat. Both thermostats need to be closed for the propane to flow.

The AC thermostat is blown in the photo as you can see the fusible wire has actually melted.

[MtnGuy]

Now I got it. Thanks for explaining that.

Does it matter if the wire from the inside switch goes lo-limit thermostat ?? The wiring diagram shows the wire going to the hi-limit switch, but mine is wired to the lo-limit switch.

[Herk7769]

Originally Posted by mtnguy

Now I got it. Thanks for explaining that.

Does it matter if the wire from the inside switch goes lo-limit thermostat ?? The wiring diagram shows the wire going to the hi-limit switch, but mine is wired to the lo-limit switch.

No, they are connected in series so it does not matter.
If you are a perfectionist, you can swap the wires top to bottom to make it like the wiring diagram says. It will not effect function at all.

The TStat is changed out as a unit. Maybe it was changed before?

[MtnGuy]

Originally Posted by herk7769

No, they are connected in series so it does not matter.
If you are a perfectionist, you can swap the wires top to bottom to make it like the wiring diagram says. It will not effect function at all.

The TStat is changed out as a unit. Maybe it was changed before?

Since it doesn't matter, I am not going to mess with it. It was probably wired like that from the factory. Both wires are red, and since it doesn't matter, I imagine the electrician at the factory didn't know which was which and just wired the unit without looking.

Thanks Again.