Two Boiler Control Wiring -Help Needed

Two Boiler Control Wiring -Help Needed

PostBy: BerksBoiler On: Sat Dec 14, 2013 4:02 pm

Hey Guys,

Trying to wire up these boilers makes my head want to explode and since the I know someone must have the knowledge on how to do this best, here goes. First, I have a Thermodynamics oil boiler (wired for domestic coil) in the house with fours zones. Its running a Honeywell L8124C aquastat and an Argo AR861 three zone control box that was installed by previous owners. Three zones are wired into the controller and one is wired into the aquastat. I have just put in an EFM 700 in a pole building that I am in the process of wiring up. Its controls are a Honeywell L7224U aquastat (wired for domestic coil) and a Taco 4 Zone control relay. There are three zones for the pole building and one ciculator connecting the EFM and the oil boiler in series all in the relay box.

My problem is: I have already laid in the thermopex line connecting the boilers along with a conduit containing a thermostat wire. The circulator connecting the two boilers is in the pole building, which is 200 ft away from the house. My plan was to use the thermostat wire in the conduit to control the circulator connecting the two boilers so that when there is a call for heat in the house the circulator starts rather than continuously running. Maybe I'm being dense, but I can't figure out a way to get a 24V signal from my controls in the house into that thermostat wire running to the pole building. Do I need to rewire the oil boiler somehow....buy some fancy control....quit being stupid...what? Wiring experts - have at it! Thank you.
BerksBoiler
 
Stoker Coal Boiler: EFM 700

Re: Two Boiler Control Wiring -Help Needed

PostBy: Dallas On: Sat Dec 14, 2013 4:29 pm

I'm not totally familiar with the models of devices, etc., which you mention. One of the devices, which I've found to bail me out on occasion is a "RIB™" .. Relay In A Box by Functional Devices. The relay can be controlled by multiple voltages, including 24VAC and the contacts can handle 115VAC (depending on the model selected). ??
Dallas
 
Hand Fed Coal Stove: Modified Russo C-35
Other Heating: Oil Hot Air
Stove/Furnace Make: Russo
Stove/Furnace Model: Modified C-35

Re: Two Boiler Control Wiring -Help Needed

PostBy: waldo lemieux On: Sat Dec 14, 2013 4:50 pm

Berks

I believe you have all the wires you need. Sounds ident. to my set up. If you hook the wires from barn to the isolated(end) switch to TT on the aquastat on efm and circ in barn to appropriate terminals on that stat(read manual I forget) I think c1 and c2 well after further review ,Wait for Rob he has all that in his head. Bottom line dont panic someone who hasnt been to happy hour yet today will be along shortly.

Waldo
waldo lemieux
 
Stove/Furnace Make: efm
Stove/Furnace Model: s-20


Re: Two Boiler Control Wiring -Help Needed

PostBy: Rob R. On: Sat Dec 14, 2013 6:09 pm

Are you going to be using the tankless coil in the oil boiler?
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Two Boiler Control Wiring -Help Needed

PostBy: BerksBoiler On: Sat Dec 14, 2013 6:42 pm

Yes, the domestic coil is used for the house.
BerksBoiler
 
Stoker Coal Boiler: EFM 700

Re: Two Boiler Control Wiring -Help Needed

PostBy: Rob R. On: Sat Dec 14, 2013 6:43 pm

Any chance there is a plug in the oil boiler where you could insert an additional aquastat well?
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Two Boiler Control Wiring -Help Needed

PostBy: BerksBoiler On: Sat Dec 14, 2013 6:49 pm

Don't know if there is another plug for aquastat...would have to rip jacket off. What are my two choices if there is a well/isn't a well?
BerksBoiler
 
Stoker Coal Boiler: EFM 700

Re: Two Boiler Control Wiring -Help Needed

PostBy: Rob R. On: Sat Dec 14, 2013 11:54 pm

You can get fancy with relays and such, or you can simply put another aquastat on the oil boiler and hook it to that thermostat wire going to your EFM zone controls. Set the aquastat to whatever temperature you need, and the circulator will run as needed to keep the oil boiler at that setpoint.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Two Boiler Control Wiring -Help Needed

PostBy: BerksBoiler On: Sun Dec 15, 2013 12:24 pm

Thanks Rob. I'll check for an aquastat plug. If I don't have one, I may just go with a strap-on aquastat. I can always go with fancy relays later. If anyone else has some ideas I will take any into consideration. Thanks again everyone.
BerksBoiler
 
Stoker Coal Boiler: EFM 700

Re: Two Boiler Control Wiring -Help Needed

PostBy: Cap On: Sun Dec 15, 2013 8:38 pm

You can use a 24v relay available at any supply house for less than $10. Use the circuit from the house to energize the relay coil thus switching the contacts from NO to NC or vice versa supplying the higher voltage to your pump
Cap
 
Hand Fed Coal Boiler: Harman SF 250, domestic hot water loop, heat accumulator