New radiant start up

dream1994

New startup on a radiant floor 2,400 sf and a dhw. ran off a 110,000 btu Knight boiler. All pipeing is done and most of wireing. I have 2 zones ran off of there own pumps with a taco rs530 controller. My ? Is how do I make the boiler and the zone control communicate what is the proper way.

hot_rod

The thermostat calls the relay box, the relay calls the pump and boiler on.

Not sure that green flow check below the pump is installed correctly, or that you should need it with the check installed in the pump?

dream1994

Yes sir, But how is it accomplished. Hi voltage or low-voltage. The directions on the taco, says hook up X1 and X2 to the boilers Aquastat . But the Boiler does not have one. boiler does not have one . Sorry for the beginners questions. I’m pretty good at the plumbing, not so much electrical. Thanks

Paul S_3

connect X1 & X2 to the heat/loop demand 1 terminals.... that will turn the boiler on....that green taco flo check is installed incorrectly should sit horizontally, it has a weighted check valve...

Ironman

It appears that you have an indirect water heater connected to the boiler? If so, you need to remove the jumper from between "H" and "ZC" on the SR503. Then run a wire from the hot "L" terminal for the SYSTEM pump on the boiler to the "ZC" terminal on the SR503. Then make sure the SYSTEM pump is programmed in the boiler control to be OFF during domestic heating. The boiler and the Taco control MUST be on the same circuit from the electric panel.

I agree with Hot Rod and Paul that the Taco flow check is installed wrong and not needed if you use the check valves that come with the Grundfos pumps.

Dave H_2

You have two different ways to turn the pumps on/off here.
The first is the Taco SR503, the second is the boiler. The terminal strip on the boiler allows you to control one DHW indirect circ, one heating circ and one boiler/primary circ.

For the line voltage wiring; Since you have two circs for your radiant, you do not want to use the boiler terminal strip for the system circ. Leave it blank. Instead, your radiant circs are wired to the SR panels along with its corresponding thermostats.
If you have an indirect tank with its own circ, wire it to the DHW terminal on the boiler and if you have primary/secondary piping, the primary circ is wired to the boiler pump terminal.

For the low voltage wiring, if you have an indirect tank, the aquastat wires to the tank thermostat terminal #13 and 14
Now from the SR panel, take the XX terminals and go to the Heat Demand terminals #19 and 20.

Dave H.

Ironman

Dave H said:

You have two different ways to turn the pumps on/off here.
The first is the Taco SR503, the second is the boiler. The terminal strip on the boiler allows you to control one DHW indirect circ, one heating circ and one boiler/primary circ.

For the line voltage wiring; Since you have two circs for your radiant, you do not want to use the boiler terminal strip for the system circ. Leave it blank. Instead, your radiant circs are wired to the SR panels along with its corresponding thermostats.
If you have an indirect tank with its own circ, wire it to the DHW terminal on the boiler and if you have primary/secondary piping, the primary circ is wired to the boiler pump terminal.

For the low voltage wiring, if you have an indirect tank, the aquastat wires to the tank thermostat terminal #13 and 14
Now from the SR panel, take the XX terminals and go to the Heat Demand terminals #19 and 20.

Dave H.

@Dave H
If it's piped p/s, then that will work. If not, there are two issues:
1. You don't have domestic priority
2. You will send 180* supply water to the floor during a domestic call.

@dream1994
How is the boiler piped? Your pic doesn't show it completely.

dream1994

You guys are awesome, lifesaver. Getting cold and there’s already water in the floor . I got some bad info on the backflow preventer‘s. Can I leave them. Or take them out

Henry

You need to support your vent and combustion air pipes independatly from the boiler. Also remember the rule of thumb for pumps: 5 diameters of pipe before and three after for a pump. We use 5 and 5 as it is easier to remember.

Grallert

I think you're going to want to remove those flow checks. There's a good chance that they could hang up in the future also might get noisy. Cant tell which model pumps those are. Do they have built in spring checks?