Dump zone valve wiring

[mma2016E]

I have a Biasi 3wood boiler plumbed in parallel with my oil boiler and looking for some advice on wiring for my dump zone. I have a Caleffi N.O. 120VAC valve, basically same thing as the old auto mag style with a spring return. I would like it to open upon power loss to allow for natural flow and also like it to open on signal from my overheat aquastat. Is it possible to wire this for these 2 applications without needing a second valve in parallel?

My plan was to wire the Honeywell 6006 aquastat using the R and B contacts (normally closed) to “open the circuit” on set temperature rise removing power to the zone valve allowing the spring to open the valve. And then with drop in temperature or power restoration in the event of an outage should “close” the contacts in the aqua-stat powering the zone valve motor back to a closed position.

Thanks in advance!

 

[salecker]

Are you running storage?

 

[mma2016E]

No storage at the moment. It’s a big house with quite a few zones so I don’t have much idle time but have been looking into that as an option down the road. This was my first winter with the wood boiler so I’m still learning.

 

[salecker]

Storage acts as a dump zone
Maybe you can plumb the dump zone to be used for the future storage

 

[mma2016E]

Storage acts as a dump zone
Maybe you can plumb the dump zone to be used for the future storage

Absolutely. In the meantime does my wiring concept sound like it will work? For some reason when I reached out to an application engineer at Caleffi he told me I would need two separate valves to accomplish what I want to do with an open on overheat and also if I loose power. I’m away at work for another month so I don’t have the valve in front of me to test.

 

[salecker]

I am not up on the different valves and what they do, but from reading your description it sounds right in theory.

 

[mma2016E]

I am not up on the different valves and what they do, but from reading your description it sounds right in theory.

No worries I’ll find out soon enough when I start playing a round with it. On the subject of thermal storage is that just added volume between the 2 boilers that’s constantly circulating between the two or does that need some type of valve that opens on demand? And would the tank need an additional expansion tank added? The wood boiler has its own in addition to the expansion tank on my oil boiler.

 

[salecker]

On my system i have it split up.
Plus it is all in a separate building.
My wood boiler is hooked just to storage,that's all it does is feed the storage.
Then i have a heat ex changer that supply the heated glycol for my house.It feed from the main line going to storage and returns to cold line going back to the wood boiler.
On the glycol side of the heat exchange i have the lines going to my house.Just out of the hot side oh the heat ex changer i have 2 close spaced tees which is my oil boiler back up tie in.
If the water coming into the heat ex changer drops below 100F the aquastate switches from the pump supplying hot wood boiler water to the heat ex changer, to powering up the backup oil boiler.With the close spaced tee's there isn't much lost to the wood side.If i know that i will be gone on holidays i will close a valve on the heat ex changer so no BTU's will bleed into the storage.
My backup boiler can sit used for months,not costing anything

 

[maple1]

Absolutely. In the meantime does my wiring concept sound like it will work? For some reason when I reached out to an application engineer at Caleffi he told me I would need two separate valves to accomplish what I want to do with an open on overheat and also if I loose power. I’m away at work for another month so I don’t have the valve in front of me to test.

That's not making sense to me. I have a normally open zone valve tied to an aquastat. Aquastat opens on temp rise and power going out does the same thing.

Edit: I didn't check out your aquastat though. And forget what mine is.