Boiler wiring

[kwired]

Such switches are typically requirement for high pressure vessels and/or when BTU capacity is over a certain level.

The higher efficiency boilers we have these days have high BTU capacity but physically small heating unit, so temp and pressure can rise rather quickly if water would stop flowing for whatever reason.

True steam boilers are naturally going to have higher pressure vessels.

The switch isn't for servicing it is to stop the heating source in emergency situation and needs located near the exit of the room so you can hit it on way out the door, usually required to be a mushroom head push to stop type of switch also.

 

[kwired]

How funny. Heating hot water.
I remember that one from years ago.
The panel sch said: hot water heater.
The insp as a joke red tagged it.
The correction. Said; please re- lable to water heater.
We laughed at that one for months.

Sorry just brought back good old job site memories.

Well a true steam boiler that is kind of what it is. You don't add cold water to those you add pre heated water, often already preheated return condensate is at least a portion of what is added when the main vessel needs more water, but fresh water gets added to to the feed tank as well and temp of feed tank is constantly maintained by heating it with steam from the boiler as needed. Only cold fill is when boiler is actually cold, after maintenance or other activity where it was shut down and allowed to cool.