adding another control relay to an existing control relay

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electricalperson

electricalperson

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Location
massachusetts
i learned how to do this when i was in school but i dont remember exactly how to wire it. can someone explain to me possibly with a wire diagram on how to add a control relay for a heating system to an existing heating system controller?

heres what i mean.

someone has a 1 zone heating system in there house and they add another circulator pump for another zone such as radiant heat or whatever. we would add a control relay to control that. i dont want the other circulator to turn on when the other zone comes on but i still want the high and low limit protection obviously for the new control relay. i dont remember exactly how to wire i know you need to remove some wires from the high/low limit
 
you are going to have to give me more info please..because you can do it the hard way which can cost you the same as a 4 zone controler..so why would you involve the high limit which is part of the firing process not the pumping proces..
 
Anyone? Okay... Hope this helps.

Last time I did this is was to add a circ pump for a HW heater loop -- should be about the same thing.

The new thermostat went to the new relay. The circ pump was fed from the new relay 120V output. The relay also had an output to run a zone valve. There was a set on contacts on the relay wired back to the boiler to fire the boiler - it went in parallel with the other zone valve contact. Wired a 120V circuit to the relay for the circ pump - and to power thea 24VAC xfm on the relay board.

I didn't have to remove any wiring from the boiler high or low limits. The limits are tied to the boiler control - in my case in the 120V going to the aquastat

The only connection to the boiler is the relay output contacts, calling for heat, which is just a parallel connection with the other zone valve switches connecting to the boiler aquastat.

I went to my local heating and plumbing wholesaler, described what I was doing - think I called it, "adding a seprate controlled circ pump" and let the counter guy pick it out. It took him a couple of tries. I looked at the wiring diagram to make sure it was what I wanted before leaving.

carl ET

PS: This is "carl the engineer's" evil twin, "carl the DIY homeowner", speaking:wink:
 
nickersonelectric

nickersonelectric

Buy a 2-zone boiler control.wires self-explanetory.dont mess with any saftys (high low limit) just your 110,t-wires and two wire 24v to xx on boiler
 
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