HW Aquatrol

1sttimeposter

<img src="file:///C:/Users/Alan/AppData/Local/Temp/moz-screenshot-14.png" alt="" /><img src="file:///C:/Users/Alan/AppData/Local/Temp/moz-screenshot-15.png" alt="" /><img src="file:///C:/Users/Alan/AppData/Local/Temp/moz-screenshot-16.png" alt="" /><img src="file:///C:/Users/Alan/AppData/Local/Temp/moz-screenshot-17.png" alt="" />Good day,

Got this Honeywell Aquatrol zone/ODR control as recommended by one of the posters here.



To avoid investing a zone expansion module, just wonder if we can combine 2 zones into one on this control by piggy-back onto one and controlled by one thermostat. Any reservation here?



Thanks in advance.

Alan (California Radiant) Forbes

Combining zones

You will then have one thermostat controlling two zones.  It shouldn't be a problem unless the zone without a thermostat control has a different heating profile.  It could over heat if it has better insulation, fewer windows, less exposed wall area, etc. or visa versa.



No harm done in trying.

1sttimeposter

good to know

..because I'm worried it may damage the control if I am to have 2 zones wired up into one on the Aquatrol...

Alan (California Radiant) Forbes

Power Requirement

The only problem you may have is that there may not be enough power available to open the zone valves when all the thermostats are calling for heat.  This control is made to control 4 zone valves and you are using 5.



But now that I'm looking at the spec's., the transformer output on the Aquatrol is 38 VA and if you are using the Honeywell 8043 zone valves, their draw is 7.2 VA each, so you should be alright.

1sttimeposter

Good point

Thanks Alan for this expert opinion!



Indeed, my 7 zone valves are all HW V8043C1041, but it says 6W on them. I don't know what the difference is between W and VA.



Would 7x6W exceed the 38VA this Aquatrol can provide? I'm hoping to do 3x2zones + 1 zone on it..... If not, can I add an extra transformer to it?



Thanks again.

Alan (California Radiant) Forbes

Zone Controller

The Honeywell AQ251 won't be able to handle that many zone valves and the transformer is "integral", i.e. you can't pop a bigger one there. 



This controller is supposed to simplify wiring and diagnostics.  You could jury rig it with external transformers and relays, but it would probably cost you as much as buying the expansion module and complicate the wiring.  Future troubleshooting would be more difficult.



Also, using the expansion module will allow you to keep your zones separate and probably reduce your energy costs in the long run, no?



As far as the electrical, W (watts) is the same as VA (volt-amps).  These zone valves are rated at .3 amps, so .3 amps x 24 volts = 7.2 VA.  The literature says 7.2 VA maximum, so maybe this is the VA draw when the valve is opening and once it's open, there is less of a draw.  Someone smarter than me can pitch in here to elaborate.