# Stupid Question - Auto mag valve



## Wood Pirate (Sep 21, 2008)

Here comes a stupid question.

What is an automag valve?  

Also, if it is what I think it is then what is the difference between an automag valve and just using a regular zone valve and manually leaving it open.


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## BrownianHeatingTech (Sep 21, 2008)

Paul_C said:
			
		

> Here comes a stupid question.
> 
> What is an automag valve?
> 
> Also, if it is what I think it is then what is the difference between an automag valve and just using a regular zone valve and manually leaving it open.



Automag is a particular brand of power-closed zone valves.

You don't have to use Automag.  Any valve which is low flow resistance, and is power-close (most valves are power-open, instead) will work.

The idea is that as long as you have power, and are not in an overheat condition, the electricity holds the valve closed.  If the overheat aquastat breaks power, or in a power failure, the valve pops open.

Joe


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## Wood Pirate (Sep 21, 2008)

So this shouldnt be used on one of my normal zones but would be good for a dump zone only?

The reason I say this is because if it has power and is not overheating it is closed so it you would never move water through it unless it overheats or loses power?


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## MrEd (Sep 21, 2008)

Paul_C said:
			
		

> So this shouldnt be used on one of my normal zones but would be good for a dump zone only?
> 
> The reason I say this is because if it has power and is not overheating it is closed so it you would never move water through it unless it overheats or loses power?



Right, my understanding that is that they are for dump zones....maybe there is some other clever use for them, but under a normal setup its just for a gravity fed dump zone.


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## BrownianHeatingTech (Sep 21, 2008)

Well, they are "intended" to be used for all zones.  An automag system uses reverse-acting thermostats to match the reverse-acting zone valves.  That means that, in the case of a failure, the zone fails open and the room overheats, instead of getting cold.

However, few contractors install new systems that way, anymore.

In a wood boiler system, it's generally only used on the overheat loop.

Joe


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## paul2e (Sep 22, 2008)

So if I have a normal closed zone that I am planning to turn into a heat dump zone. It sounds like the easy way would be to use the automag zone valve in combo with the automag themostat. Power out = zone open /power on = control via thermostat. Is there any way to do this with the Taco zone valves already in place?


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## BrownianHeatingTech (Sep 22, 2008)

paul2e said:
			
		

> So if I have a normal closed zone that I am planning to turn into a heat dump zone. It sounds like the easy way would be to use the automag zone valve in combo with the automag themostat. Power out = zone open /power on = control via thermostat. Is there any way to do this with the Taco zone valves already in place?



No, you would either have to replace the zone valve, or cut tees in before and after it, so that the reverse-acting zone valve can be installed in parallel.

Joe


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## Wood Pirate (Sep 30, 2008)

MrEd said:
			
		

> Paul_C said:
> 
> 
> 
> ...



I am still a bit confused.  If I use the largest zone in my house as my "Dump Zone" by installing a Normally Open zone valve rather than a Normally Closed Zone valve then I cant just put in a specific thermostat that I can adjust to get heat?  

I thought as long as you have a normally open zone valve and the correct corresponding thermostat that you can operate that zone as you would any traditional zone.  I thought the only difference was that when the power went out the zone would open to prevent overheat


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## steviep (Oct 1, 2008)

If you go to the Benjiman wood boiler home page they have a pretty good diagram that shows how to use a dump zone.


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## BrownianHeatingTech (Oct 3, 2008)

Wood Pirate said:
			
		

> I am still a bit confused.  If I use the largest zone in my house as my "Dump Zone" by installing a Normally Open zone valve rather than a Normally Closed Zone valve then I cant just put in a specific thermostat that I can adjust to get heat?
> 
> I thought as long as you have a normally open zone valve and the correct corresponding thermostat that you can operate that zone as you would any traditional zone.  I thought the only difference was that when the power went out the zone would open to prevent overheat



Yes, you can.  The only issue is that selection of reverse-acting thermostats is limited, and they are often special-order items; so, if it fails, you may not be able to get a prompt replacement.  You would also potentially have to add a relay to operate the boiler's end switch, depending upon the exact installation technique.

Joe


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