Weird zone valves

Ken C.

A coworker and I went on a service call today. Customer has boiler with tankless coil, the tankless was recently abandoned and an indirect water heater installed. After that, the customer complained that her baseboard would get hot. We suspect the problem is as follows: Before the indirect WH was installed, a call for hot water would activate the oil burner, but not the circulator. Now, a call for hot water does operate the circulator (only one) in order to circulate hot water through the indirect. There is a flowcheck on the space heating system feed, but we believe that the three zone valves for space heating are allowing heated water to pass through. These zone valves are made by Automag (Jessup, PA), model # AA 3/4-14. They have two wires each. This is the first time either of us has ever seen this brand of zone valve. Is anyone familiar with these? The house was built less than 10 years ago, so these aren't ancient.
Also, are we correct in our assumption that these "Automags" are not 100% positive shutoff valves? We plan to go back and replace these zone valves with Taco zone valves, which are 100% positive shutoff. Any other suggestions?

Robert O'Connor_6

Automags

are a positive shutoff valve . They are DC powered thru a rectifier at the 24 volt transformer and must be powered to close.

Maybe you should contact them and get the literature yoiu need and save alot of labor and parts.

I have found them to be trouble free. Argo has a nice zone control panel for them.

Regards

Robert

ME

Dale

Auto mag

These are good simple zone valves. The difference ( besides the DC coil) is that they are normally open, meaning with a power loss they open. The 3 wire stat hookup closes TT and cuts power to the valve on a call for heat to that zone. I would check that there's a magnetic field on the zone valve coils with none of the stats calling. Just touch the top with a steel screwdriver. Since most DHW tank hookups have a separate pump rather than using the system circulator if this HW system was set up just as a zone the chance of pushing some water past the zone valve seems possible, kind of like when pumps are mistakenly put in series. I would call auto mag at 800-451-2002 and see what they say.