View Full Version : Zone not heating, but is showing active

03-06-2012, 05:59 AM
I have one Zone which does not seem to want to heat up. My TACO box shows the Zone as active and the thermostat appears to be working as well.

Some things I tried:
Swapping thermostat with another verified one
- doing this had the same issue. troubled zone did not work and working zone did.

Verified TACO zones by turning each off multiple times and back on
- troubled zone does light up on the TACO box

Looked for leaks
- No leaks found

Given this I can rule out the thermostat and possibly the taco box. Below are four pictures of my setup:

1st Picture, the Thermostat Appears to be fine

2nd Picture, The TACO Box

3rd Picture, The troubled Zone (Center)

4th Picture, All Zones

One thing to note, This all seemed to happen at the same time I pulled some electrical wire through the same hole the Thermostat wire goes through, but given the TACO indicator turning on and off with the thermostat I'm chalking that up to a coincidence.

03-06-2012, 01:25 PM
Can you feel the circulator pump turning on when the zone calls for heat? Is the pipe hot above the circulator when it is supposed to be on? All it takes is a little bit of air in the zone to prevent the circulator from pushing the water through. Have you tried purging the line for that zone?

03-06-2012, 03:37 PM
How easy is it to purge the line for a novice?

03-06-2012, 05:23 PM
No one, easy answer...it depends on what you have and how it is connected. If you're lucky, there are purge valves at the radiators or at the high point in the system. Is the zone that is not heating the one highest up? If so, it is likely air. It's one of those things that you have to be there to see.