todays problem service call

jaybee

Well here goes, went on a call today for too much heat. Discovered that system had a bad zone valve that was allowing water to flow in problem zone even though it was not calling.Well, sodered in a new valve,cut out the old one. Now mind the bad zone valve was a valve that had only 2 wires and it was named automag never seen it before.So i wired in the zone valve useing only the motor portion and nto useing the end swicth.Okay valve didint work!!! determined the fuse that protect the transformer was blown.Replaced it. Now another problem.Every time i set the t-stat to call burner shuts down and when i turn it down it turns on the burner.Well, i had to call for help and help came and solved the prblem.he rearanged the wireing in the t-stat. There was three wires red, white,@blue. He took the blue wire off its termonal and put it on the terminal with the white wire.Everything worked fine.I would like to know about that t-stat with 3 wires if anyone could lead me in some type of direction it would be apprciated.

Mark Hunt

Motor open, motor close


Old Honeywell T-stat?

That sounds like the system had a motor open/motor close ZV at some point, and the T-stat to boot. No-one ever changed the t-stat?

Mark H

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jaybee

problem call

It was new i think they had just install the t-stat.how do this type of t-stat work im trying to understand why it reacted the way it did.

clammy

auto mag

I believe most if not all i've seen are normally open power closed dc zone valve there was usally a recitfer with a end switch made by the control board you could just change the t stat .Wire the honeywell end swicth to the board and wire in a seperate 24 v tranny just for the honeywell.For your custemer tell them to change them all (automag ) that recitefer board is a coulpe of bucks and automag valve when and if avabable are not cheap about 85 to 100 bucks haven't had to replace one in years but still run into them they do have a manual open set screw on them good luck .That three wire stat is usally reverse contacts been a while peace clammy

Tony_8

what you have (had)

Is an AutoMag zone valve system. It is a 3 wire system. The valves are solenoid type and power to close. On a call for heat the R-W terminals of the stat close and turn on the boiler, and R-Y open to de-power the valve. It can be a little confusing because the terminal board and thermostat designations quite often don't exactly match.

Anyway, the zone valve itself probably wasn't bad. If the coil goes the valve fails open. If the fuse on the board blows ALL the valves open. The only other thing (electrically) that can cause it is the thermostat going bad. If soldering was done in the system recently by someone who uses too much solder, a ball of it can get stuck under the seat and not let it close. Rare, but possible.

You can tell if the coil is bad with a nail. When the zone is off the coil is energized and the end is magnetized, holding the nail. Turn up the stat and the nail falls

Dale

Current automag number

Tony's explanation is correct. However the automag product is now more extensive. I called them at 1-800-451-2002 a few minutes ago to ask if they had a web site, no they don't but were as friendly as ever. If you call they'll send you literature and tech sheets on their product which is extremely simple to wire and install and fails open not closed. The 3 wire stats worked as tony explained but a 2 wire stat and relay works fine too. They make a side coil version zone valve that fits in the small space inside a baseboard.