I think HVAC tech created a dangerous situation - please help me fix it!

Rooster1

I’m running out to the store, but before I do I just wanted to thank all of you for your help. 

I went for it and filled/purged myself. We will see how the next few days go, but I seem to have a fully functional system at the moment.

I confirmed that I can use upstairs zones in isolation and pull heat, which was the main issue since last winter. 

I also have the boiler up to temp with 170 degrees supply and 150 degrees return, and the gauge showed less than 20psig the entire time.

Thank you, thank you, thank you!

JUGHNE

At those temps your boiler should stay happy!

I was running at maybe 145 out, don't recall the return temp.
But it was obvious my bypass had failed.

Rooster1

I also learned that the air purger on the main supply from the boiler had the plastic cap on the automatic bleeder screwed down tight, so it wasn't working to allow air to escape. When using a flashlight to shine through my pex tubing, I have always been able to see bubbles here and there - now that I have a functioning air purger, should I expect these bubbles to gradually be vented as I am running zones?

mattmia2

I suspect that when the expansion tank failed and the air from the other side of the bladder entered the system and ended up blocking or restricting flow in the zone that wasn't heating correctly. The cap being closed on the auto air vent was the missing piece to this.

Rooster1

Matt, it was the entire upstairs that couldn’t heat, UNLESS a lower level zone was running. So we had an 80 degree basement for the second half of winter.

JUGHNE

Rooster1, on your boiler there is a 1/2" plug under the return pipe.
That is an air eliminator port built into the boiler castings.
It is a good place for an auto air vent.

I did not see any other air eliminator on your system other then the little ones on the manifolds.

Rooster1

JUGHNE said:

Rooster1, on your boiler there is a 1/2" plug under the return pipe. That is an air eliminator port built into the boiler castings. It is a good place for an auto air vent. I did not see any other air eliminator on your system other then the little ones on the manifolds.

Thanks. It does have an American Air Purger on the main return to the boiler by the basement ceiling.

Rooster1

Now to troubleshoot smaller issues - I have two zones that don’t flow - one on the main and one upstairs. 

I have Stadler powerheads. For my valves, which position is open vs closed? When I remove the powerhead, is the valve open when the plunger is let out from the manifold or when it’s pushed in?

If nobody knows, I’ll have my wife use a thermostat in a known working zone while I watch the head move. I’m at work now.

Colorado_Dave

Am I the only one who got momentarily nauseated seeing the PVC, before realizing it was the combustion air?

Yes, I have seen a GV improperly vented with PVC, it wasn't pretty. 

Rooster1

Colorado_Dave said:

Am I the only one who got momentarily nauseated seeing the PVC, before realizing it was the combustion air?

Yes, I have seen a GV improperly vented with PVC, it wasn't pretty. 

Exhaust vent? Jeepers.