Mixing valve on Stadler manifold chattering

Ed Lentz_2

I have a system I installed approx 15 years ago. It consists of a Stadler Viega Basic Heating system controller with mixing valve control and a Stadler Viega manifold with the mixing valve solenold/actuator. The actuator has begun to chatter like it is trying to do something but cannot make up its mind. I am concerned that the Basic controller has gone south. Is this a possibility? If so what are my options? The system has worked pretty good all this time. Is there a different controller?
Thanks for any ideas BTW I installed the system myself with the guidance of a master plumber.

Ironman

Post a pic of the manifold.

If you have the motorized actuators, they can be replaced with thermal ones. That may be all that's wrong with it.

GW

I'd take the actuator off and try to replicate the noise and then determine what the issue is

Ed Lentz_2

With it off the valve it still chatters. I had it off earlier and I replaced it onto the valve. I don't understand why it would be active in the summertime. I thought the system only actively ran once a month when it was in WWSD.
Thanks

Ironman

Post a pic of the control.

Ed Lentz_2

Here ya go

Ironman

That's a rebadged Tekmar.

I had that same one acting strange on a recent call. Disconnecting the power and re-booting it seemed to cure it.

Ed Lentz_2

I thought it looked like a tekmar I had seen a long time ago. I will power it down and reboot it and see what happens. If it needs replacing I want to do it before I really need it. Thanks

Ed Lentz_2

OK so powering it all down did not stop it from chattering later. So I guess the control is toast? is there a way to run without the mixing ? I have the manifold with the valves, can;t I just adjust the valves and keep the water moving?

Ironman

How will you prevent the water temp being too hot for the floor?

EBEBRATT-Ed

I am assuming the actuator is 24 volt?? Is it two position -powered open and then powered closed? or spring return??

If you can figure out the electrical requirements of the actuator you could disconnect it from the controller and then power the actuator from another source to test the actuator and valve.

Ironman

Ed, the Tekmar modulates the valve's position.

Ed Lentz_2

Ironman,
Is that an open/ closed or a infinite position type of control. I know the tekmar controls according to the temperature curve. Just trying to come up with a way to fix this without costing a bunch of money.
Thanks

hot_rod

I think it is a floating 24V signal, tekmar is about the only control offering that anymore. check all the wiring connections, a loose or bad terminal or connection could be preventing adequate current.

Applying 24V to it should take it full open and see if it is the valve itself causing the noise, or the control not sending adequate signal.

Ed Lentz_2

There are 3 wires. Open / closed and neutral? 24vdc or ac?

EBEBRATT-Ed

@Ironman,

I know.
I don't really consider two position or floating as "modulation" but that's just me. Modulation to me is series 90 Honeywell, pneumatic air pressure, 0-10vdc or 4-20ma but I guess floating is modulation because it can stop in any position

@Ed Lentz

If it's two position floating yes, open, closed and common or neutral.

I would assume 24v ac. Check it with a meter. The voltage should be marked on he actuator

Ed Lentz_2

I have yet to take it off and put a meter to it or power. So if it isn't floating then it fully opens and will fully close when the correct voltages are applied ?

hot_rod

Ed Lentz said:

I have yet to take it off and put a meter to it or power. So if it isn't floating then it fully opens and will fully close when the correct voltages are applied ?

I'm pretty sure it is a modulating valve. There would be no reason to have it connected to a tekmar control and use a 3 port valve if it was just on off.

Caleffi still has some floating 24V 3 way valves in our offering. Although that is a somewhat outdated control signal, most all controls now are going with digital signals, and can be driven from mod cons in many cases.

Remember if you start troubleshooting or playing with digital controls you need a true RMS meter to read the signal correctly. A standard VOM will lie to you

Ed Lentz_2

Was able to get a pic. To me it looks like a open/Close from the literature

hot_rod

Almost certain that it is a floating 24V actuator, the wiring schematic has nothing to do with the operation. You can find replacements on e-Bay.

Same info if you look up the old tekmar data for the control.

Really no reason to have a valve like that on a manifold unless it adds some mixing or temperature control value.

Basically it allowed you to use small diameter piping and feed 180F to the manifold, the valve mixed right at the loops. Viega still offers that pump bloc in a composite version now.

hot_rod

I found out a bit more about the 24V float, we have a former Honeywell control guru in our company.

Often called a 3 point control the signal either turns the motor CW, CCW, or off. It has a time function involved also as the control needs to know the time from full open to full close. So it is basically screwing the valve from either direction.

Kevin calls them the "poor mans" modulating control, very inexpensive and simple to implement.

Ed Lentz_2

Thanks hot rod

I found the Manuel for them. Although it didn't say so, I got the impression that "something" needed to know how long to apply the control voltage. So that might be easily figured out. It also has a clutch assy to keep itself from screwing itself into the ground. So to speak. Lol

Ironman

We Did a boiler replacement on job today that had two of those. They seemed to have a vibration and slight chatter noise even when the Tekmar's were in WWSD. So, I don't think there's a problem with the Tekmar, but you probably need a new actuator if it's too noisy.

Ed Lentz_2

Why would it charter if it was in wwsd if the tekmar was ok Supposedly it isn't in use at all.

Ironman

You'd have to ask Tekmar.

Ed Lentz_2

I guess so. Thanks for your experienced help, guidance.

hot_rod

In WWSD there should be know power at the actuator that could cause a motor induced chatter. A volt meter could confirm that, or just remove the wires and see if the noise stops.
The pump isn't running by chance? It could be a noise caused by flow trying to go thru the valve while in an off position.

Ed Lentz_2

Hmm. I don't think the pump is running when I hear that noise. I will remove a lead and see what happens, probably put a meter on it too. I know the tekmar cycles the pumps every 3 days or so in wwsd but I am down there every day. That manifold looks real familiar.

JeffM

The Basic Heating Control (and most tekmar controls for this type of actuator) do supply power to the actuator during WWSD, to make sure the valve stays closed and you don't get ghost flow. You should find 24V power on the wire that drives the valve closed.
A little clicking is normal for those actuators in that circumstance (its the internal clutch), but if it's really noisy replacing the actuator should fix it.