Oil Burner - zone not sending hot water

Pellet_Guy_2016

I have 3 zones for my oil burner (New York), and 1 of the zones is not sending hot water to the pipes when the thermostat trips. Other 2 zones are fine. Had the unit serviced 2 months ago, said all was good to go.

Is it possible that they forgot to turn a lever back on? Like the one in this photo, upper left?

DZoro

Can you back up and take a picture with all the piping?
It's hard to tell but it looks like you have a domestic hot water coil, and that valve goes to it, which is off.
But if that is the case it would have nothing to do with a heat zone...maybe..
D

HVACNUT

Agree. That's not a valve for heat. Post more pics from about 8 ft away and different angles. Describe which is the problem zone. Could be air bound, bad circulator or zone valve. Bad thermostat or relay. Broken wire, Gremlins, etc.

Pellet_Guy_2016

Here you go. Thanks for the help, would love to fix this asap.

Pellet_Guy_2016

The affected zone is my sun room. Upstairs and downstairs main work fine. Pipe is cold to touch. I've tried to trace it back via my basement but it's tough as many run into the foundation to various points.

Those pics good enough, or do you need more?

DZoro

Thanks! Great pictures!
Looks like 2 zones have been recently changed? The 2 with pex, is one of those the problem? Like @HAVACNUT said you maybe air bound in one of them.

Pellet_Guy_2016

Been in this house for 1.5 years, no change done since I've been here. Just had it serviced in June.

How do I tell which of them is the potential issue? The previous owner left no labeling.

If the issue is air inbound, how do I solve? Bleed out from that zone on the pipe itself?

DZoro

Turn off all three thermostats. Then turn one thermostat on, go to the pumps, one of those pumps should turn on that goes with that thermostat. Pumps can be very quiet, so you may have to close and open one of the valves at each pump to listen for water flow. To determine which pump is on. Then label accordingly. Repeat again.
Each of those blue boxes are a control box for each pump.
D

Pellet_Guy_2016

Okay - detective work done.

The not-working zone is the blue box farthest to the left—which runs to the red box farthest to the left in all the pics.

The red box itself is slightly warm, but the pipe connecting to it is cold.

What now?

DZoro

Are you able to confirm that the pump is getting power to it?
When you open and close the valve next to that pump can you hear any water flowing.
What type of registers do you have and do they have any bleeders on them?
D

STEVEusaPA

I don't see a red box, but I see a gray one, which is your aquastat.
You can start by checking the relay (blue box). Remove the low voltage wires from the thermostat (really just one), jump out those 2 terminals and see if the relay kicks on and sends power to the circulator. It should also kick on the burner if your temperature isn't at high limit.
I hope that's oxygen barrier pex.
The only good thing about that boiler is its very easy to properly clean. And that's the only thing..

DZoro

A picture further left may also be helpful.