Proper flow through boiler.

Guy_2

What is the reccommended delta T through a boiler? I have a CI Burnham v76 oil fired boiler piped primary/secondary with valves for adjustment. Thank you.

Brad White_32

Normally 20 degrees

but may be as wide as 40 degrees. The limitation is the return water temperature which for oil should not fall below 130 degrees. Some say 140 to play it safe, the dewpoint of flue gasses varying with combustion composition.

Point being, the narrower your delta-T the lower you can run your supply water temperature (150 in case you want to keep above 130). If you reduce flow to 40 degrees you have to run 170 F supply at least.

I would stick with 20 degrees.

Guy_2

Thanks Brad.