Have HVAC Questions? Ask an HVAC Expert for Answers
What do you need the relay for?
Do you have a model number for the relay?
If you mean an RIBU1C, that's not a suitable relay. You need a Taco SR501 or similar.
There is no diagram unless I draw one but it's pretty simple. Here is the diagram for the SR501You connect your Taco zone valve end switch leads (2 & 3) to R & W on the relay. Line voltage to N & H (as shown) 5 & 6 N/O to the thermostat terminal on the low voltage terminal strip on the WM97 corresponding to the line voltage zone you have the system pump wired to. If you have more than 1 zone valve all the valve end switch leads go to R & W on the SR501,
Like I said there is no drawing and what I just described to you is how you use an SR501 as an isolation relay. Check the Taco link in my last reply if you don't know how to wire the zone valves.
You have to buy a relay. The pump relays in the boiler perform an entirely different function. The relay that's most commonly available and is suitable for this purpose is the SR501. The relay you mentioned initially is not suitable it's not a switching relay. I'm not aware of any switching relays for less money than an SR501 (~$45)