Grundfos Alpha2 for Radiant Heat

VancouverG

I’m thinking about switching my Taco 007 to Grundfos Alfa2 15-55. I have 6 zones and of course the Taco pumps the same if 1 or 6 zones are calling for heat.  I have two questions
1) my Taco 007 gets power thru the Taco ZV406 (picture attached). My original plan was to get the terminal box Alpha2 instead of the line cord.  However My understanding is that the Alpha2 auto adapt feature would reset if the power is cut off after the call for heat is satisfied.  So pointless as it would have to relearn each day.  Is there a work around for this ?
2) what is a good GPM to have and have others that are using it happy or would you say stick with the Taco 007

hot_rod

The ECM delta p circs can just stay powered up. They only draw about 7 watts when in idle mode, hence the power cord and plug.
You could wire it into the relay, either switched or constant power from the box.
The two circs are similar in capacity. An ECM will both adjust its flow and also save you some power

VancouverG

So I don’t need the terminal box model then I could go with the line cord model ?  The reason I ask is that the line cord model is more available to me.  If I’m understanding you correctly if I plug it in with a line cord there will not be any circulation as the zone valves are shut and so there is no where to circulate to. 

Also one more question I have heard others complain that they are only get .4 or .5 GPM on auto adapt.   Is that a possibility?  I mean what is a good GPM that I should expect 

GGross

I have the corded model grundfos in my own house and am very happy with it

Dave H_2

The 007e will do what you are looking for. The most efficient circulator is the one that is powered down. It will speed up and slow down as the actuators open and close

VancouverG

Dave H_2 said:

The 007e will do what you are looking for. The most efficient circulator is the one that is powered down. It will speed up and slow down as the actuators open and close

So basically if I wire into my Taco zone controller box it will shut down when not needed and then adjust the flow based on how many zones are calling?  So is this line cord or terminal box? Also it doesn’t need any temp sensor on return does it ?

VancouverG

VancouverG said:

So I don’t need the terminal box model then I could go with the line cord model ?  The reason I ask is that the line cord model is more available to me.  If I’m understanding you correctly if I plug it in with a line cord there will not be any circulation as the zone valves are shut and so there is no where to circulate to. 

Also one more question I have heard others complain that they are only get .4 or .5 GPM on auto adapt.   Is that a possibility?  I mean what is a good GPM that I should expect 

Mine needs to be installed horizontally so my understanding is if I can find it would need to be the FR model (rotating flange) I guess you are using on auto adapt mode and finding adequate flow 

Jlinde37

I too don't understand the ecm thing. So basically the alpha should be powered on all the time and it's ok to deadhead it with a zone valve closed? Does the ecm stop the rotor from turning at all until the zone valve is opened? I too have an alpha on a radiant manifold and I don't use the auto-adapt as it's switched on with the zone relay. 

Dave Carpentier

I use my Alpha2 in delta-P mode and relay switch it on/off via end-switches in the zone actuators.

hot_rod

Jlinde37 said:

I too don't understand the ecm thing. So basically the alpha should be powered on all the time and it's ok to deadhead it with a zone valve closed? Does the ecm stop the rotor from turning at all until the zone valve is opened? I too have an alpha on a radiant manifold and I don't use the auto-adapt as it's switched on with the zone relay. 

I don’t think  it stops spinning completely, it needs to maintain some reference point to know when a valve opens. I’m not sure what rpm it spins when you see a 7W readout. Barely spinning I suspect

Zman

Auto adapt is over rated hype. Just switch in and put it in one of the constant pressure modes,

VancouverG

Sounds like Taco 007e is a better option 

Joe Mattiello

The 007e ECM will run most efficiently because it runs close to synchronous speed, or less slip like traditional PSC 007. As Dave said, you can get more efficient pump than one that powered down when there’s no load.hope this helps