Condition 1. Programmer in Timed=OFF No live to Heating Ctl board, and no power to pump BP. If flow switch operates, then RLY (after time T) will operate and put power onto pump SP via connection (2b) … all fine
Condition 2. Programmer in Timed=ON Provides live to heating controller … and in the event of it calling for heat will provide a switched live feed from ‘pump ’ and I can use that to power the boiler pump BP, via RLY connection (1a) There are a number of thermostats, zone valves etc. all under control of Heating Control board so can only run pump BP when there is a 'Pump' live signal.
If the flow switch operates when boiler is making a heat call, I need pump SP not to operate, as there would be no power to (2b) that requirement is met
The issue I have is if there is no call for heat and flow switch operates I need pump SP to run … so I need to get live feed to it at that point ……… currently stumped. Am I missing something that I can achieve given the DPDT contacts in relay and SPDT in the programmer. Otherwise I will have to add in another RLY