4 inch steam valve

Snowmelt

I have 2 steam zone valves i am going to change out the motor, 1 is 4 inch and inside of a flange zone valve, the face of it is all rusted out, it looks like the motor itself sits on a FRAM AND HAS 4 SMALL BOLTS HOLDING IT in, but how do i take this pig apart?

Intplm.

Not sure how to take them apart.
Can you give us a look? Pictures?

Snowmelt

Here are two pictures 1 is the 2 inch , other is 4 inch, ironically they both have the same motor .

clammy

Do they still work meaning if disconnect the linkage and see if you can manual move the stem if not then whole valve replacement may be need . Having the valve position horizontal may not be the best I would do a little research on that . There s usually a couple of small bolts holding the motor onto the bracket in the one pic I can see them but they are rusted I would use a grinder and grind the bolts and if memory serves there’s a clip that attaches to the stem .i think w all the rust it might be hard to locate it s been a while since I ve worked on them . Last one I did they used vise grip type of control ,clamp it open and let her rip Just look at it closely and you should be able to figure out it’s not that difficult you can also see if there is any info on internet show dis assemble or exploited view would help u see through the rust lol peace and good luck clammy

Snowmelt

Thanks clammy, I have John from Honeywell coming first week of December, there Honeywell 24 volt. I wonder if I can by the actuator and the motor.

The Steam Whisperer

Wow, a 4 inch valve can handle a couple million btu's ... most be a really big place.

Snowmelt

This place has 2 water boilers, 2 steam boilers and one furnace with ac.

Mike_Sheppard

That linkage needs to be replaced too. And by the looks of it the valve stem packing as well.

Linkage is a Q5001. Manual linked below. The mod motor is probably an M9174 or M9184 can’t quite tell from the pictures.

Those can be a pain. Make sure to read the directions.

https://customer.honeywell.com/resources/Techlit/TechLitDocuments/63-0000s/63-2425.pdf

Snowmelt

Thanks mike, the motor is a 24 volt , I gave the number to the supply house. Let me ask is the valve steam replaceable?

Mike_Sheppard

All of Honeywell’s mod motors are 24v. They contain an internal mounted transformer. They can either be supplied 24v from an external transformer or you can feed outside source of 120v to the optional internal transformer which then supplies 24v to the mod motor’s circuit board.

The valve is rebuildable. Here is the manual:

https://customer.honeywell.com/resources/Techlit/TechLitDocuments/77-0000s/77-5613.pdf

Snowmelt

mike last question on motors, can I use a taco zone control board , so I can see which of the two zones go on ? I couldn't even see where the wiring went because it was all rotted. I love seeing which zone went on and off for trouble shooting purposes.

Mike_Sheppard

I’m not sure on that one. It depends on how they’re controlling it now. Those mod motors use what’s called Series 90 control. They use a 135 ohm bridge circuit. Sometimes referred to RBW. R being the common (neutral). Connection R-B drives the motor open, R-W drives the motor closed. There are many different ways of accomplishing this. I am not familiar with the Taco control you’re referring to but my guess is it probably isn’t compatible with this.

But there are a ton of other ways they may be controlling this. They could be using a matching Honeywell Series 90 control to modulate it or they could even be using something as simple as a thermostat to make R-B on a call for heat which would just drive the motor fully open.

The job I dealt with used a brand of control I can’t remember, but it was wireless. There was a control in the boiler room that had wireless thermostats out in the building. When the thermostat would call for heat it would tell the control to close a contact which would make R-B at the mod motor and drive it fully open. As soon as the connection between R-B was broken the motor would spring return to the closed position.

I think your best bet for now is to figure out where the wires go and how they are controlling it. Then let me know and I could give you a better recommendation. Also pop the top off the mod motors and see how they are wired inside. Typically you will have T1 and T2 (24v Power), R, B, and W. But Honeywell does make an add-on board that can convert it to a 0-10v signal rather than 135 ohm. I highly doubt that’s what you have, it I have seen it done before.