No heat in 2 zones

Jackgiz

I'm at at daughter's house for Xmas and she tells me that some of the rooms are cold.  Checking in the basement I found 4 zones controlled by Honeywell V8043 valves.  2 of the loops are hot and 2 are cold. 

I pulled the cover off one of the cold zones and disconnected the Tstat wire.  The mechanism in the power head moved.  I took the 2 screws out of the power head and removed it from the valve body.  The little stem coming out of the valve body turns freely, very freely.  Could something be broken inside the valve?  I moved the stem to the end stop in both directions and the pipe still stayed cold.  I checked every valve on the loop that I could find and they all appear to be open.  This loop goes to a second floor bedroom.

Could the valve itself be stuck closed but the stem still turn?  Like I said the stem moves very freely almost like it's not connected to anything.

Could there be an air bubble in the system?  How much pressure does the circulator pump put out?  Can it pump a column of water up to the second floor?

icesailor

No heat in 2 zones:

The circulator has no effect on the pressure on the second floor.

Read the string here on getting air out of convectors.

You need to raise the system pressure. You need to by-pass the fill valve. But you need to be careful. The valve is probably broken and needs to be replaced. Raise the system pressure to 18# to 20# and it will probably start flowing. The two valve heads that are hot are probably to the upstairs zones that are not working. The valves haven't had power taken off since the last time the thermostat was satisfied.

Can you take pictures of the boiler fill?

Steve Whitbeck

air in system

What is the system pressure? Do you have cast iron baseboard or stand up radiators.

If the system pressure is at least 12 PSI and you have cast iron - try venting the air out of them. there should be a bleeder on each radiator. It sounds to me like you have air blocking the water flow.