One Zone out of Three Not Heating

[Dmwesq]

I have a US Boiler K2 with three heating zones. 2 out of the three are working. The third zone is not delivering heat. The pipe itself feels warm to the touch, but the baseboard is cold.

The thermostat - a Nest Learning one, looks like it is operating and is set to 72 and shows orange as if calling for heat. I may try to swap that with a regular thermostat just to rule that out. I could call Nest to troubleshoot it but that is always a painful experience.

I was also told to try to bleed the zone as that could also be the issue - I'm a little tentative to try even though I have seen it done - don't want to screw anything up if I can avoid doing so.

Thoughts on any other things to check as to why one zone just stopped delivering heat?

 

[Fitter30]

One pump for three zones with zone valves? Take a few pics of boiler, piping pump and zone valves.

 

[Sponsor]

 

[Dmwesq]

One pump for three zones with zone valves? Take a few pics of boiler, piping pump and zone valves.

 

[Fitter30]

Zone not working if it's a honeywell below wires there is a thin sheet metal lever push it to the other side and the slot gets bigger push level think its down hold lever down and hook it into the slot to hold it open. Taco valve has a push button. Push down turn knob to open let go of button should hold valve open. Line should get hot . Taco pump is mounted wrong should be mounted with motor level not straight up. Model of pump for install manual. Have a volt meter that can read 24 vac? What brand of valve isn't opening?

 

[Dmwesq]

Zone not working if it's a honeywell below wires there is a thin sheet metal lever push it to the other side and the slot gets bigger push level think its down hold lever down and hook it into the slot to hold it open. Taco valve has a push button. Push down turn knob to open let go of button should hold valve open. Line should get hot . Taco pump is mounted wrong should be mounted with motor level not straight up. Model of pump for install manual. Have a volt meter that can read 24 vac? What brand of valve isn't opening?

The valve not working is the Honeywell one marked UP. The Taco valve was installed by plumber and I will mention what you suggest and see what they say when they are next here - which may be soon if I can't get the zone to work. So if I slide the lever on the Honeywell to the left and pull it forward to lock it into place what should theoretically happen?

 

[Fitter30]

The valve not working is the Honeywell one marked UP. The Taco valve was installed by plumber and I will mention what you suggest and see what they say when they are next here - which may be soon if I can't get the zone to work. So if I slide the lever on the Honeywell to the left and pull it forward to lock it into place what should theoretically happen?

They sell replacement actuators
www.supplyhouse.com/Honeywell-Home-40003916-026-Replacement-Head-for-V8043E-Zone-Valves

 

[Fitter30]

The valve not working is the Honeywell one marked UP. The Taco valve was installed by plumber and I will mention what you suggest and see what they say when they are next here - which may be soon if I can't get the zone to work. So if I slide the lever on the Honeywell to the left and pull it forward to lock it into place what should theoretically happen?

Valve should open. They also make a kit for a new actuator reusing the brass body. Yellow wires with thermostat calling for heat should be 24 vac to open the valve Don't have 24vac check R to C at thermostat. Should have 24vac. Have 24 vac disconnect R touch to W valve should open.

 

[Dmwesq]

Turns out the problem was with the thermostat - just another sign I need to replace the Nest products with something that is more reliable.