Thank you Mystery for that link. Going to have to make up my own bypass using T pieces in-between the flow and return pipes, Cant get it that close to the valve but it think it will help.

Almost finished rebuild of 300tdi Auto with full Puma Bulkhead/dash. Have been told that when connecting up the heater pipes from the rear of the TDi to the Puma heater control valve i have to include a bypass loop because of the heater valve fully closing. Thoughts/solutions/ideas and...