old cast iron boiler temp

john_181

Hello,

I have an old cast iron boiler 432,000 Btu from the 1930's and I would like to know what you pros think:

what is a good minimum temp setting to set on my aquastat?

should the circ pump run all the time or just when the boiler reaches a certain temp?

It is a water system gas fired, i just installed an outdoor rest controller too.



Thanks

Alan (California Radiant) Forbes

Outdoor Reset

I presume you have cast iron radiators?  That is a fairly large boiler; you must have a big house.



Your outdoor reset control should be able to monitor return water temperatures.  Make sure it limits return water temperatures to above 130° to protect your boiler from condensing .  And to answer your question, minimum supply temperature should be 150° or above.