Low delta t?

Dave_61

We recently repiped my copper tube boiler with a buffer tank (Ergomax). In the manual for my boiler, it says that a flow of about 25-30 gpm through heat exchanger will give a 20 degree delta t. We have a Taco 0010 pump pushing water through boiler (max flow 30 gpm). With a temp gauge on inlet and outlet of boiler, we currently have a delta t of 10 degrees. Would there be anything else that could affect this besides flow through boiler? That would mean by chart for my boiler that flow is 50 gpm, which is impossible with the 0010 pump.
The only other hooker is that my boiler has a 2 stage burner. If only 1 burner was on (150 K btu vs 300K btu), could that cause lower delta t?
Thanks.
Dave

Brad White_33

One side versus the other

For any heat exchanger to perform, you need to have the secondary side doing it's job too. Part of this is knowing what all the other part of the system is doing.

For extreme example, if your secondary side is not operating, you may start with a low delta-T until the HEX warms up. Then your delta-T will be minimal because no heat is being extracted on the secondary side.

That is the broad view without a picture of the setup in my mind's eye. Can you establish the other factors for us?

Brad

Boilerpro_3

Yes

with about 130,000 output and 30gpm, your delta tee would only be around 10F.

Boilerpro