Manually opening Erie zone valve sends power to the end switch?

chapchap70

When manually opening a Honeywell zone valve with end switch, the circulator does not run; this is what I expected.  When I manually opened an Erie zone valve with end switch, (this boiler has one of each) the Alpha circulator display lit up even though the thermostat was not calling.  It surprised me that the circulator ran since I don't know where it got power.



Both zone valves seemed to work normally all year where the control sends power to the zone valve motor which in turn sends power to the end switch circuit, turning on the circ. 



Either I wired something wrong or the Erie works differently than the Honeywell.  Am I missing anything?

STEVEusaPA

I think...

It just detected some flow. Did you remove power to the valve before switching it to manual?

billtwocase

it will

make for a split second, but that's it. The end switch will not be active in the manual position. Why did you do that? Is there an issue?

ColoradoDave

Alpha Circulator

If you're referring to a Grundfos ALpha circulator......  if the pump is plugged into a 24/7 outlet (instead of feeding it's power from the boiler), then opening the valve allows it to move water.

The Alpha pump was designed to constantly check for head pressure on it's output by an action we've called "ticking".  Periodically the pump bumps the impeller to check for head pressure.  As soon as you open any valve (by T-stat or manually) the Alpha senses that the head pressure at it's output has dropped and revs up to move water.  Depending on it's setting (Flow, Pressure or Auto), it will ramp up to get the desired output.  So in this scenario, you don't need the endswitch signal to trigger the pump.



Disclaimer:  NOT an engineer, just a heating mechanic.  So my technical explanation is a layman's explanation.  So while the explanation may have a few flaws, it basically explains the Alpha pumps operation. 

chapchap70

No issue with the valve

I was purging the zones after doing some work on the baseboard.  I did not disconnect power in the end switch circuit.  I thought the Erie and Honeywell zone valves would behave in the same way when manually opening the valves; either both would turn on the circulator or neither.



I do not have the plug in Grundfos Alpha.  I might not have noticed it getting power if it was a 007;  I noticed the display lighting and staying lit until I shut the zone valve.  It did not light the display at any time while purging the zone with the Honeywell zone valve.