I am trying to decide on ASHP sizing. Using the heat loss spreadsheet I believe I can get by with an 8.5kW ASHP.   The problem is that I want a 300l DHW tank. All the sellers i find with the Ecodan seem to pair the 8.5kW version with maximum 210l tank. I am considering to go up to the 11kW ASHP so I can get the larger tank - is there any reason 'not' to go ahead and oversize the ASHP?   The UFH will run off a buffer so there shouldn't be cycling issues with that part of the s