Two Boiler Control Wiring -Help Needed

This forum is for common products and questions such as chimney installations, CO detectors, coal bin designs and a variety of other general topics that do not fit into the other forums.
Post Reply
BerksBoiler
New Member
Posts: 5
Joined: Sat. Dec. 14, 2013 2:25 pm
Stoker Coal Boiler: EFM 700

Post Sat. Dec. 14, 2013 3:02 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.

User avatar
Dallas
Member
Posts: 744
Joined: Mon. Nov. 12, 2007 12:14 pm
Hand Fed Coal Stove: Modified Russo C-35
Other Heating: Oil Hot Air
Stove/Furnace Make: Russo
Stove/Furnace Model: Modified C-35
Location: NE-PA

Post Sat. Dec. 14, 2013 3:29 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). ??

waldo lemieux
Member
Posts: 2261
Joined: Sun. Sep. 30, 2012 8:20 pm
Stove/Furnace Make: efm
Stove/Furnace Model: s-20
Location: Ithaca,NY

Post Sat. Dec. 14, 2013 3:50 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 don't panic someone who hasnt been to happy hour yet today will be along shortly.

Waldo
When faced with a seemingly impossible task, my grandfather always said "can't never can, untill try comes along"


User avatar
Rob R.
Site Moderator
Posts: 11343
Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Sat. Dec. 14, 2013 5:09 pm

Are you going to be using the tankless coil in the oil boiler?

BerksBoiler
New Member
Posts: 5
Joined: Sat. Dec. 14, 2013 2:25 pm
Stoker Coal Boiler: EFM 700

Post Sat. Dec. 14, 2013 5:42 pm

Yes, the domestic coil is used for the house.

User avatar
Rob R.
Site Moderator
Posts: 11343
Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Sat. Dec. 14, 2013 5:43 pm

Any chance there is a plug in the oil boiler where you could insert an additional aquastat well?


BerksBoiler
New Member
Posts: 5
Joined: Sat. Dec. 14, 2013 2:25 pm
Stoker Coal Boiler: EFM 700

Post Sat. Dec. 14, 2013 5:49 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?

User avatar
Rob R.
Site Moderator
Posts: 11343
Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Sat. Dec. 14, 2013 10:54 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.

BerksBoiler
New Member
Posts: 5
Joined: Sat. Dec. 14, 2013 2:25 pm
Stoker Coal Boiler: EFM 700

Post Sun. Dec. 15, 2013 11:24 am

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.

User avatar
Cap
Member
Posts: 1581
Joined: Fri. Dec. 02, 2005 10:36 pm
Hand Fed Coal Stove: Harman SF 250, domestic hot water loop, heat accumulator
Coal Size/Type: Nut and Stove
Other Heating: Heat Pumps
Location: Lehigh Twp, PA
Contact:

Post Sun. Dec. 15, 2013 7:38 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
Lehigh Twp.
Northampton Co., PA

Post Reply

Return to “Coal Bins, Chimneys, CO Detectors & Thermostats”