hey,
just found out a strange behavior of your heat exchangers

they take the heat information out of the input slots, which has some strange behavior, as the recipe in progress has already consumed the input when working:

1. take a heat exchanger and fill 1.5 times the needed hot water/pressured water (max heat)
2. fill now the cold water part in though some piping.
3. watch how the water in the output is not 100 degrees (Celcius)

In the case I pre filled the heat exchanger with 2 times the needed hot fluid I got what I wanted.
In case I prefilled it with 1.1 times needed fluid, the output didn't even heat up.

It depends on what recipe you were using. If you exchange heat between the same fluid, you will always need 2x the fluid on the hot side vs the cold side. So it is not strange behavior but just that the math required it to be so.