Manifold connections, mixing valve question

[jclark1]

If someone can help, let me know if I'm seeing this system operation correctly. The cold water in is on the right and the hot water out is on the left (this part I know). The mixing valve is on the hot output side for the regular hot water supply and for the hydronic heating, what I don't get is how the mixing valve works if the cold water comes into the system after the valve.What you can't really see in this picture is that the hot water out from the tank is hooked up right under the mixing valve and also to the timer operating what I presume to be a recirculation unit for the hydronic heating. The other copper pipe at the bottom of the pic is just the tpr out. I assume this setup is strictly for the hydronic htg system. I never did find where the cold supply t's off to feed the rest of the townhouse so I guess it's in the wall before this point.

[jclark1]

Unless of course (as I looked at the picture again)I was looking at the flow backwards.Are the hydronic space heater inputs the lower manifold? It pisses me off that I didn't get more time to figure out the system but I had one of those "this one shouldn't take too long, right?" agents. This was towards the end of the inspection so I was rushing, trying to get done.

[Brian E. Kelly]

My head hurts just looking at that James.

[David P. Valley]

Attachment 3895

I think the plumber (if he was one) was confused on this install.

[tnoisaw]

Truthfully, I don’t know what the heck is going on with this mess. It is very sloppy work. i think I would have to be there to track everything to figure this one out.

[phinsperger]

Follow the arrows in this pic

[Brian E. Kelly]

Originally Posted by phinsperger

Attachment 3898

Follow the arrows in this pic
Attachment 3899

Wow Paul. Nice work.

[jclark1]

Thanks Paul. That's (after I thought about the system a second and third time) is pretty much what I thought. Thanks for confirming with a great visual aid.

[dgagne1]

I would hope that this was for heat only, and if so I would like to have seen a backflow preventer on the system somewhere seperating the domestic from the heat. It realy is a mess, It appears that this was a creative installation by someone in training pants. I like the outlet buried inside the piping for the W/H. The flue connection apears to be a rubber connection with clamps, maybe some concern there. Was there a seperate water heater somewhere?

[dgagne1]

I would hope that this was for heat only, and if so I would like to have seen a backflow preventer on the system somewhere seperating the domestic from the heat. It realy is a mess, It appears that this was a creative installation by someone in training pants. I like the outlet buried inside the piping for the W/H. The flue connection apears to be a rubber connection with clamps, maybe some concern there. Was there a seperate water heater somewhere?

[dbucknavich]

What are the gold arrows? Not many of these in Phoenix. I'm pretty sure I'm happy about that.

[dbucknavich]

Do the gold arrows represent the domestic supply? I'm trying to guess before I am told. By the way Paul, that is really impressive how you labeled the diagram. Great job.

[phinsperger]

Hi Dylan,

The gold arrows represent the tempature reduced water. That is done by the mixing valve adding a bit of cold water to the hot water. It's not my inspection so I don't know where it goes after it goes through the wall but yes it is very likley that becomes the hot water supply for the fixtures in the house.

[jclark1]

Yes, it is the hot supply to the fixtures. Up here zonal, hydronic space heating is being installed in a lot of new construction. I would assume this is a pretty typical installation, though I guess I'll find out in the future.

[apolillo]

I see this a lot in condos, but it is usually less complicated at the manifold.

Anatol