NEW home-SECOND ZONE

1002 Views 13 Replies 4 Participants Last post by RH913RH, Dec 25, 2015

RH913RH

Discussion Starter · Dec 25, 2015

Hi All
I need help wiring a second heating zone.
The system is a peerless gas boiler controlled by a Honeywell L8148E aquastat.
When the primary zone thermostat calls for heat it turns on the boiler and the circulator.
The second zone was wired through a relay which only turns on the circulator when its thermostat calls for heat.
This is a cold start boiler so it is possible for zone 2 to call for heat and wind up pumping cold water.

I know I need another relay so I can move zone 1 circulator control out of the aquastat, but I cant figure out how to connect both t-stats to the aquastat so the boiler will start when either t-stat asks for heat, but not back feed to the other relay and kick on the other circ.

Any help would be appreciated.
Thanks in advance
Ralph.

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jmon

· #2 · Dec 25, 2015

On my boiler I use a taco 3 zone switching relay recommended by Beenthere. This switch controls everything. Don't know if it will work for you. Beenthere help me set mine up about 4 years ago. Everything still working fine.

Please post some pictures of your boiler setup. Thanks.

Please wait for the hvac techs to respond.

http://s3.supplyhouse.com/manuals/1351150925280/85270_PROD_FILE.pdf

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jmon

· #3 · Dec 25, 2015 (Edited)

Some pictures of my 2 zone boiler set-up. You will see the green taco switch at the top (second pic); That baby controls everything.

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RH913RH

Discussion Starter · #4 · Dec 25, 2015

That looks like it would work.
I will get more info from mfg.
thanks a lot
Ralph

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supers05

· #5 · Dec 25, 2015

Old school way....

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RH913RH

Discussion Starter · #6 · Dec 25, 2015

Hi supers05
thank for the help
the diagram isn't very clear
there is a transformer in the aqua-stat that turns on the boiler and the circ. for zone 1, and a transformer in zone 2's relay switch which just turns on zone 2 circ., which one is the existing low voltage circuit

I'm old and been out of school a long time

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supers05

· #7 · Dec 25, 2015 (Edited)

Adjusted the diagram for you.

PS: both "control relays" are new and will need to be added to your existing setup.

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beenthere

· #8 · Dec 25, 2015

Using a zone panel is easier and cleaner looking.

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RH913RH

Discussion Starter · #9 · Dec 25, 2015

Hi Beenthere
I was looking at the TACO 2 zone switching relay as suggested above.
I'm a little confused as to where the low voltage comes from.

Is it from the T T connection on the Aqua-stat? or do I need a separate external transformer?

Ralph

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beenthere

· #10 · Dec 25, 2015

The panel has its own transformer built into it. It provides the 24 volts to the thermostats. The end switch is what gets connected to the TT terminals of your aquastat.

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RH913RH

Discussion Starter · #11 · Dec 25, 2015

Thanks Beenthere
You cleared that up.
From the wiring diagram from Taco it look pretty straight forward. but I didn't see the transformer.

Ralph

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RH913RH

Discussion Starter · #12 · Dec 25, 2015

Hi Beenthere
Just came from my sons house where I'm working on the 2 zones. Both t-stats have a red and white wire only.
Just to review.
using the Taco 2 zone switch. I would connect the 2 wires from each t-stat to the appropriate terminals in the switch, then run 2 wires back to the Aqua-stat from the end switch and attach them where the zone 1 t-stat Was originally connected.( T T) terminals
Then provide 110 volt power to the switch and attach each circ to their terminals.

Is this correct?

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