Altherma flow temp issue

[mad fridgie]

Excuse my ignorance, what is SAP (some sort of average heat load over a season) Thats a monster of a house, (heating requirment does seem small)
Why would you want to increase the split over the heat pump by reducing the flow rate, this only increases discharge pressure (increasing elecrtrical input and reducing energy output)
why are you concerned with theoretical flow temperatures, you stated that some areas are at temperature.
In my opinion very small splits are all positive (even heat distribution). Is this on a timer or does the system run 24-7 (the ability)
I do not understand how you are getting approx 2C split across the manifolds, yet getting a 5C split between the F&R of the circuit feeding the manifolds.
Are the feed temps to all mainfolds the same or different.
Is the system new (how long has in been running)
plus you heat pump will not give is rated output when at the present working conditions.
I would run 24 -7, reduce water set point temperature, (look at how the elements are controlled, not sure about your unit), never reduce flows.