Fuel oil boiler thermostat settings

[bobk]

Greetings. I would be very grateful if someone could tell me what these two thermostats control on my boiler, and what would be a reasonable setting. (See attached image.) The one on the right appears to set the upper limit for the boiler temp, but I'm not sure about the one on the left.

Thanks!
BK

 

[Haworthplumbing]

It could be your operating stats. Depends what your running off your boiler but if it's base board heating you could run it between 150-170. That way the boiler will not short cycle. The high limit stat should shut down the boiler if it over heats. It is a safety

 

[Haworthplumbing]

What are they set for? Can't tell on my screen

 

[bobk]

sorry -- it is a baseboard heating system. The one on the right is set to 190, and the one on the left is 125. The burner comes on at around 165. So what is the 125 setting?

Thanks for your help; here are some better pictures.

 

[havasu]

Just a note, if you click on the yellow bar above the image, the image will increase in size.

To the original poster, just for my own knowledge, I Googled CB656 Immersion Control and found many user manuals for these heater controls and I believe they could help you somewhat. Living in California, these heaters are only seen in books.

 

[bobk]

Thanks. I guess it's a matter of how the thing is wired up. Is it possible that the CB656 is a low limit for the boiler temp? I'm working on a theory that the room thermostats must be calling for heat in order for the burner to kick in at 165. If the room thermostats are not calling for heat, then this "secondary" CB656 takes over to keep the boiler warm. Does this make any sense at all?

 

[Haworthplumbing]

That makes seances. Then the return water would not come back to cold causing the boiler to condensate. It's hard to tell with out looking at the wires. How ever your operating stats in the box too the left of that should keep the boiler running at temperature. That switch
Could also tell the boiler too shut off if the temp gets too low. So if you were out of oil the boiler would not be circulating cold water. Where does the wire coming out of the bottom
Of that stat go?

 

[bobk]

Here are a couple more pictures. The wire runs to one of the three switch boxes that handle the 3 room thermostats -- we have 3 zones and 3 circulators.

Thanks for your help.