Hot water zone on steam boiler

Safir

Add a hot water zone off my steam boiler with a separate thermostat can someone help me with the wiring part? I am planing to use a aquastat so it can fire burner without producing steam for upper floors. 

Jamie Hall

The aquastat can be wired in parallel with the steam thermostat. Then either one will fire the boiler. Presumably you have a circulator pump on the hot water loop -- that would be controlled by the thermostat in the space you are heating with the loop.

EBEBRATT-Ed

@Safir

Yes as @Jamie Hall said install an aquastat that has contacts that "make on temperature fall" and wire from the aquastat a 2 wire cable in parallel with the thermostat that runs the boiler for steam. So it will connect to the same terminals on the boiler control that the thermostat connects to.

Then for your circulator buy a Honeywell RA89A switching relay. There are others by Taco & Argo that are =.

Run a two wire cable form you new hot water zone thermostat to the new relay mounted near the boiler and connect terminals R & W in the thermostat to T & T in the relay.

Then you need 120 volt power off the boiler to power terminals 1 (hot) and 2 (neutral) in the relay. Also pull a green or bare ground wire or use a metal raceway.

From your new circulator pump wire to the new relay white to term #2, hot for the pump to term #4. Put a jumper between terminal 1 & 3 on the relay if not factory installed.

Run a ground wire from the circ pump to the relay

Safir

Thanks for the prompt response yes I have a circulator on the loop. I have a taco single zone relay, l4006 aquastat and thermostat will these work? Thanks

EBEBRATT-Ed

The aquastat will be ok. Don't know what you have for a t stat or relay

Safir

I have a sr501-4 1 zone relay will that work? I have a Honeywell thermostat battery operated

Safir

Also when upstairs call for steam I would like circulator to run also. The wiring Jamie explain will that happen?

Jamie Hall

Safir said:

Also when upstairs call for steam I would like circulator to run also. The wiring Jamie explain will that happen?

No. The circulator would only run when the its own thermostat is calling for heat. If you want both the upstairs thermostat and the zone's own thermostat to run the circulator, then you will need a relay controlled by the upstairs thermostat. If you want the hot water circulator to run either when its thermostat is calling or when the upstairs thermostat is calling, but not necessarily when the aquastat is calling, then you need two relays, one controlled by each thermostat, and the wiring gets interesting, though not complicated.

Safir

Ok thanks I guess it's not important to have it run on both thermostat will keep you posted how it goes thank you again

mattmia2

Safir said:

Ok thanks I guess it's not important to have it run on both thermostat will keep you posted how it goes thank you again

I don't see why you would want to do that. You have 2 independent zones without it, with it you run the risk of overheating the hot water zone.

Safir

On the relay the part that say connect to tt on boiler where do I connect that ?

HVACNUT

Safir said:

On the relay the part that say connect to tt on boiler where do I connect that ?

TT (or R-W) on the SR501 go to the thermostat for the new zone. 
Terminals 5 and N.O. 6 get wired in parallel with the wires for the steam thermostat. 

Safir

Ok so terminals 5 and 6 wire parallel with steam thermostat and the aquastat too the same way?

EBEBRATT-Ed

@Safir

There's two ways to do this.

1..You can use the aquastat to maintain a hot boiler 24/7 then use the new thermostat for the hot water zone to start the circulator.

That is called a non integrated control

OR

2. Or you can use the aquastat as a limit control for the boiler (the boiler will be cold unless the steam or hot water thermostat is calling for heat)

Then the new hot water thermostat will run the boiler (if below the aquastat setting) and run the new circ pump.

This is an integrated control

Which one do you want? Does your boiler heat Domestic Hot Water?

#2 involves more wiring

Once you decide I will post a wiring diagram

Safir

Yes the #2 is exactly what I am trying to do. No not using to heat domestic water

Safir

For the record I have a crown Bermuda steam boiler

EBEBRATT-Ed

@Safir

this should do it

Safir

Thankyou very much that makes it so easy

Safir

Will post results when finish

Safir

I have been thinking with the wiring diagram if the aquastat is satisfied and upstairs thermostat is calling for heat wouldn't the aquastat prevent the burner from firing? Maybe I am overthinking but I ask anyway

EBEBRATT-Ed

Ok this is how it works:

Steam side:

Steam thermostat calls for heat, boiler fires up and makes steam, radiation gets hot,rooms heat thermostat is satisfied boiler shuts down.

Hot water zone"

Thermostat calls for heat, new relay pulls in and starts circulator pump. It will also start the boiler IF the boiler water temp is below what the aquastat is set for. So if the boiler is already hot from steaming and the hot water zone calls for heat the burner will not fire until the aquastat calls for the burner

The purpose of the aquastat is to limit the boiler water temp so the boiler won't make steam (and heat the steam radiators) with only the hot water zone calling for heat

Safir

Wow interesting well explain thank you

Safir

I finally get around to this I wire as shown its working burner is firing baseboard warming up but I notice once it hit temp I think Aquastat needs to be reset manually for it to fire again. Any suggestions?

Safir

This is the aquastat I am using l4006e1109 break on rise

EBEBRATT-Ed

@Safir

Yes you bought the wrong aqustat the L4006e is a manual reset you can't use that.

You could use a L4006A get one with an adjustable differential

Safir

Ok will do thanks

Safir

I replace the Aquastat works perfect. Would like to thank everyone here for helping out. 

DPH2023

I’m trying to wire up a zone of baseboard to this steam boiler and I’m having trouble with the control wiring, I’m looking for the diagram you posted a link for in this thread but I can’t open it for some reason. Looking for integrated control

EBEBRATT-Ed

@DPH2023

Attached is a PDF drawing. I don't know what you have for a system or controls. It would be better if you started a new thread and posted a few pictures and more information