terms in a hot water heating system and help needed on wiring

I am trying to figure out how to use the Taco SR504-exp-4 Switching Relay with my Alpine 105 gas boiler due to the changing from one zone to 3 zones. I am not very clear some terms on the instructions. Please help me. My system doesn't have a hot water sub-system attached. It is a winter water heating only system.

System pump ---- the pump for individual heating zone.
DHW pump ---- the pump for the hot water sub-system(for shower, kitchen, not for the winter water heating system)
Boilder pump ---- the pump close to the boiler and help the water circulating to the boiler
Primary pump ---- the boiler pump?
Priority ---- for DHW only?

For the wiring, I have modified a sample wiring diagram coming with the Burnham Alpine 105 boiler installation manual. Please help me wire it right. The one with red lines is my wiring plan.

 

Systems can be plumbed & pumped in a variety of ways. With Primary/Secondary configuration the boiler-loop is referred to as the "Primary", and the loop(s) to the radiation are referred to as "Secondary". Many simple single-zone systems can be set up with just one pump doing it all.



In this two pump system the orange triangle in the schematic could be referred to as either the boiler pump or the primary pump. The blue triangle would be the secondary pump.

Any zone can be given priority status in a zone controller, but when there is an indirect fired tank, that is what is usually the priority zone. It will usually have it's own pump, since it's flow requirements can differ from the boiler or radiation flow requirements.