Downstairs Zone not heating

Reply

  #1  
Old 03-09-19, 07:19 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
Angry Downstairs Zone not heating

Hello everyone,

I am at my wits end with my system. I have a simple two zone heating system (upstairs and downstairs) controlled by Honeywell zone valves. Both thermostats are Nest Thermostat E's. I have been having problems with my downstairs zone, I can't make it turn on and call for heat to save my life. It doesn't turn on for the thermostat and it won't turn on if I hard wire my power wire (R and W1 wired together) to my heating wire. My upstairs zone works perfectly fine. I am assuming there is a wiring problem but I have no idea where.

How my system is currently wired is the main set of wires from the boiler connect directly to the upstairs zone valve. From those connections, there is a second set of wires that then connect to the downstairs zone valve. So the wiring is down in series, boiler connects to upstairs zone valve which then connects to the downstairs zone valve. I am not sure if this was done correctly, this was how the wiring was down before I purchased my new home. I have attached a simple diagram showing what I mean.

Trying to fix the issue, I have replaced the wiring between my thermostat and my zone valve, I have replaced my zone valve motor, I have replaced the transformer on my boiler, and I have replaced the wiring between my downstairs and upstairs zone valves. The zone valve continues to not fire when called.

I am absolutely stumped and am looking for any possible help! Really would prefer to not call someone to come out!

Thanks,
omni0
 
Attached Images  
Sponsored Links
  #2  
Old 03-09-19, 07:27 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
One other thing I wanted to add, I have also tried swapping the thermostats. Both thermostats work upstairs, and both don't work downstairs. So definitely not the thermostats themselves.
 
  #3  
Old 03-09-19, 07:33 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 50,990
Likes Received: 162
Welcome to the forums.

Please realize there are many ways to wire these systems and most I've seen have been kluged together. Your description is not helpful.

Are you saying you have zone valves on different floors ??

The wiring should be very simple and very clean. You have two zone valves and two thermostat. You should have a transformer that runs the zone valves. You should have a thermostat cable from each thermostat to each zone valve. The upstairs thermostat should not be tied in at the downstairs thermostat.
 
  #4  
Old 03-09-19, 07:47 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
Hi,

Sorry if my description was not as clear as I wanted it to be.

Answering your questions:
The zone valves control different floors but they are both installed just above my boiler.

I have a transformer wire that goes up and then has both zone valves connected to it via a wire nut. The connection is located next to the upstairs zone valve.

Each thermostat has their own wires that connect to each zone valve (both of these have been recently replaced as well to install a common wire).

The upstairs thermostat is connected directly to the upstairs zone valve, and the downstairs thermostat is connected directly to the downstairs zone valve.
 
  #5  
Old 03-10-19, 07:06 AM
Member
Join Date: Jan 2008
Location: Southeastern Pennsylvania
Posts: 2,938
So just to be clear, you are saying in post #4 that this statement from post #1 is NOT correct:

So the wiring is down in series, boiler connects to upstairs zone valve which then connects to the downstairs zone valve.
 
  #6  
Old 03-10-19, 10:50 AM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
Each ZV has to be wired separately and not in series. There must be a separate 24V transformer and not the one in the aquastat. That being said.

The wiring goes: From the XFORMER - STAT - STAT - ZV (YELLOW) - OTHER YELLOW - XFORMER. That wiring completes your 24V circuit that will open the ZV on a call for heat from the stat. The 2 RED wires from the ZV go to TT on your aquastat at the boiler.

This wiring will open the ZV on a call for heat and when it opens will make an end switch which will send power to TT and turn on the boiler and pump. The 2 YELLOW WIRES for the stat and the 2 RED WIRES for the boiler.

Duplicate this for each zone. You can use same transformer for power.

Hope this helps a little.
 
  #7  
Old 03-10-19, 11:05 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 50,990
Likes Received: 162
Ok..... no problem. Can you post some pictures of the zone valve wiring.
How-to-insert-pictures.
 
  #8  
Old 03-10-19, 03:33 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
zoesdad,
After closer inspection you are indeed right, these zone valves are not in series. Sorry about the confusion. I am attaching pictures below that should hopefully help show what I am dealing with, unfortunately the way it was installed in not very helpful in troubleshooting.

Spott,
I quickly went through my wiring and it does in fact look like that is how my wires are currently set up. I am posting pictures below to hopefully show what I am dealing with.


Pictures:
Not sure why my pictures are sideways, they are right side up on my computers. All pictures on my end are rotated 90 degrees clockwise from what you see here. My explanations are based on what I see on my computer, not the post. Let me know if this needs to be fixed... In any case...
First picture shows my system. You can see on the pipes the run across the top 2 zone valves. The one towards the top left is my upstairs zone, which is working fine. The one to the right is my downstairs zone. They are both placed at the "input" valves for the zone.

The second picture shows the wiring of the transformer itself. Green is connected to R while red is connected to C.

The third picture is showing the blue and white wires connecting to the boiler Thermostat.

Fourth picture shows the wiring done at the upstairs zone valve. Here you can see the white wire that connects to the thermostat, this wire has three smaller wires inside (White = Heating, Red = Power, Green = Common). Moving left to right in this image, you can see that one of the yellow wires from the zone valve connects to the Heating wire from the thermostat. Next, the other zone valve yellow wire connects to the Common thermostat wire as well as the red wire from the Transformer (connected to the C terminal on Transformer). The other red wire in this wire nut heads over to the downstairs zone valve. The wire nut directly to the bottom right of the prior one connects the Power thermostat wire to the R terminal of the transformer. The other green wire goes to the downstairs zone valve. The last two wire nuts contain the connections from the two zone valve red wires to the boiler thermostat (blue and white wires). The other blue and white wires in these wire nuts connect to the downstairs zone. The yellow wire is unused and is not connected to anything. I will be trimming this wire down once I have the system fully operational.

The last picture shows the wiring at the downstairs zone, the valve that is not working. I apologize for the messy wiring, but I didn't want to tie it all up if I had to change anything again. Moving from the bottom to the top, the bottom wire nut contains one of the red wires from the zone valve and connects it to the white wire that should connect to the boiler thermostat. The wire nut just to the right of it contains the other red wire from the zone valve that connects to the blue wire. This should also connect to the boiler thermostat. Directly above this wire nut is another wire nut that has a yellow, green and red wire. The yellow wire connects the zone valve to the green common wire of the downstairs thermostat and to the C terminal (via red wire) of the transformer. Directly to the left of this wire nut, you have the red power wire of the thermostat connecting to the green wire that should connect to the R terminal on the transformer. At the top, you have the last wire nut that connects the white heating thermostat wire to the other yellow wire from the zone valve.

I am really sorry for the lengthy paragraphs, just wanted to walk you through the wiring the best that I could. Please let me know if any other information would be helpful!
 
Attached Images      

Last edited by omni0; 03-10-19 at 03:35 PM. Reason: Added explanation of pictures
  #9  
Old 03-10-19, 06:03 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
UPDATE.

I am starting to think its the actual valve itself. I just noticed that it gets completely stuck in the on position when the lever is pushed down to Manual control. When moving the lever on the valve powerhead there is resistance all the way but it never goes back down. The lever then can be freely moved with no resistance whatsoever. This is with the thermostat NOT calling for heat. This is opposite to what the upstairs valve is doing, which is working perfectly fine. That valve's lever has resistance and then when I release the lever it returns back to its starting position.

So is it looking like the entirety of the valve needs to be replaced?
 

Last edited by omni0; 03-10-19 at 06:05 PM. Reason: added text
  #10  
Old 03-10-19, 06:28 PM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
In your 4th pic remove the wire nut with the green & red wires and the one with 3 wires and check your voltage. You should have 24V. Try it with the stat on & off.

If the stat is calling there should be no resistance on lever. When stat is off there is resistance to open manually.
 
  #11  
Old 03-10-19, 06:43 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
In your 4th pic remove the wire nut with the green & red wires and the one with 3 wires and check your voltage. You should have 24V. Try it with the stat on & off.
Just so I understand, you want me to measure the voltage between the transformer and the thermostat with the power on and off?

If the stat is calling there should be no resistance on lever. When stat is off there is resistance to open manually.
I made sure the thermostats were off for both zones when I tried the levers on the valves.

The lever on the upstairs zone valve has resistance when you push it to open manually and when you release the lever it goes back to it's starting position. If you push on the lever again, there is resistance again.

The lever on the downstairs zone valve had resistance at first until it was pushed all the way to the manual open position. The lever then never returned to its prior starting position and it can now be freely moved with no resistance. If you move the lever back to the Auto position and attempt to push back there is no resistance now.
 
  #12  
Old 03-10-19, 06:49 PM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
It sounds like the plunger in the ZV itself is stuck. Not the head but the body.

If you take the reading at those points you will see if you have 24V through the stat and the ZV. which should activate the end switch and send power back to TT.
 
  #13  
Old 03-10-19, 07:01 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
My thermostats actually let me know how much power they are receiving. The power readings my downstairs thermostat is reporting are:

Battery: 3.922 V
Voc: 33.70 V
Vin: 33.70 V
Iin: 200 mA (i)
 
  #14  
Old 03-10-19, 07:13 PM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
What does it read when you call for heat and does the other one read the same. 33 V from a 24V transformer.
 
  #15  
Old 03-10-19, 07:42 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
I am not sure exactly if it is a 24 V transformer. It was recently replaced by a local HVAC company when my boiler was being serviced during the purchase of my home. The sticker I found is hard to read because of everything in the way but I believe I see 24 VAC 75 VA...?

Upstairs thermostat is reporting similar voltages compared to the downstairs thermostat. Numbers for both thermostats when they are not calling for heat and calling for heat.

Upstairs not calling for heat:
Battery: 3.912 V
Voc: 33.57 V
Vin: 33.57 V
Iin: 200 mA (i)

Upstairs calling for heat:
Battery: 3.912 V
Voc: 31.69 V
Vin: 31.69 V
Iin: 200 mA (i)

Downstairs not calling for heat:
Battery: 3.922 V
Voc: 33.70 V
Vin: 33.70 V
Iin: 200 mA (i)

Downstairs attempting to call for heat:
Battery: 3.922 V
Voc: 33.33 V
Vin: 33.33 V
Iin: 200 mA (i)
 
  #16  
Old 03-10-19, 08:08 PM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
The simplest thing to try now is to remove your 2 heating wires from the stat and jump them together, and everything should start. If not you have a wiring problem. If your plunger is still stuck in the open position you will get heat in that zone when the other calls anyway until it's fixed.

Can you post a pic of your stat and wiring connections.
 
  #17  
Old 03-10-19, 08:14 PM
Member
Thread Starter
Join Date: Mar 2019
Location: United States
Posts: 9
I just had someone else try turning the downstairs thermostat up while I sat next to the boiler waiting for something to happen. The downstairs zone valve is trying to do something... I can hear the motor start and see the spring move slightly but then it just stops, assuming it has to do with the plunger as you suggested. Sounds like the entire valve needs replacing.
 
  #18  
Old 03-10-19, 08:32 PM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
Sounds like that's the first thing to do then.
 
  #19  
Old 03-11-19, 05:44 AM
Member
Join Date: Nov 2012
Location: USA
Posts: 3,763
Likes Received: 7
Hi, in post 8 the pic seems to show red,green and yellow connected together, where is that white cable going? Those 2 yellow wires from the end switch on the valve should go directly to the aquastat.
Geo
 
  #20  
Old 03-11-19, 10:29 AM
Member
Join Date: Oct 2013
Location: United States
Posts: 2,688
Likes Received: 8
G,
The 2 yellow wires are for the stat side, and 2 red go the boiler TT. You have them reversed.
 
  #21  
Old 03-11-19, 11:52 AM
Member
Join Date: Nov 2012
Location: USA
Posts: 3,763
Likes Received: 7
Got it, my mistake..................
Geo
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes