2nd Zone no heat, thermostat not working.

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Old 10-03-11, 08:31 AM
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2nd Zone no heat, thermostat not working.

I dont think its a thermostat issue. The thermostat used now and the one previous have not worked for as long as my fiance has owned the home (2 yrs). Yes she sleeps in the cold upstairs with no heat in the winter, she likes it with her nice down comforter, weirdo.

I "jumped" the connection at the thermostat where I connected the Rh and white wires together but this did not seem to turn anything on in the boiler. I assume this would turn furnace on, simply setting it like a thermostat would.

I think this is a safe way to assume its not a thermostat issue but something actually on the boiler somewhere. Is there a connector on the boiler or something I could troubleshoot next?
 
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Old 10-03-11, 10:25 AM
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2nd zone heat,

on some zone heating systems thermostats go to a control panel of sorts that determines which stat is calling for heat or a/c . check to see if it is hooked up , it might be located near the heating unit or on it somewhere. just follow your wires from the stat that you think is not working.
 
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Old 10-03-11, 04:09 PM
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Billium, how many zones? one up and one down?

Are the thermostats heat only or do they also control the A/C system? (in other words, two wires ? )

Can you take pics? We need to see what you've got in order to help much...

Set up a free account at Image hosting, free photo sharing & video sharing at Photobucket and upload the pics there. Come back here and place a link to your PUBLIC album. Please be sure the pics are in focus, well lighted and large enough for old dudes to see. Cell phone pics not acceptable. Take some of all the controls you see with wiring on them, and also of the entire system from a distance and several angles so we can see everything.
 
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Old 10-03-11, 04:29 PM
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You also need to tell us if you there are zone valves fort each zone or just pumps. There could be a control panel as bbaum mentions that could have a problem, or the thermostats could be wired directly to the zone valves. If there is a problem at the zone valve, the boiler will not turn on.
 
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Old 10-03-11, 09:47 PM
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Great questions guys, I can upload a photo or two tomorrow. There are only 2 wires and the thermostat does not control ac as there isnt any. Its an upstairs zone, its one of 2 total zones in the house. One zone per floor. The middle floor zone 1, works perfect. I can check the furnace tomorrow for the type of connection down there. There are wires that seem hastily taped up. Now I am handy with electrical to a point, I have a multimeter if this were to help determine stuff. Ill update tomorrow.
 
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Old 10-04-11, 03:58 PM
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The multimeter will be helpful.
 
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Old 10-13-11, 09:24 AM
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Back again

Sorry for the delay, school started up recently. I have done some more investigating. I used my multimeter to test continuity by connecting the two wires in the thermostat and testing the other ends together at the furnace. They had continuity! So I guess I can rule out the bad wiring.

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As you can see in the photo the wires are pretty badly connected and covered. I went through each twist cap and redid them, when I am done with this ill find a nice way to contain these wires. The last thing I did was traced the zone two wires up into what I have learned is a zone valve. The installer wrote upstairs zone and downstairs zone on them. Now I dont know where to go from here. Does this mean my next step is to repair/replace this zone valve?
 
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Old 10-13-11, 03:58 PM
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Bill, since you know the wiring is good, next thing we want to know is whether or not the zone valve is opening when the thermostat calls... you see, the valve can open, but the 'endswitch' inside the zone valve could be defective and not tell the boiler to fire.

So, go to the basement, and ask yer gal to stand by the thermostat and call you on yer cell phone. Tell her to turn the thermostat all the way up and listen for the whirring of the motor inside the zone valve head.

This is a very basic diagram of how a zone valve can be wired, and yours may be:



The YELLOW wires from your zone valves are the motor leads, and the RED wires are the endswitch leads. There is no electrical connection between the red and the yellow.

What happens is that the thermostat closes the 24 vac circuit to the zone valve motor. The motor runs and opens the valve. There is a 'cam' inside the valve that then pushes on the ENDSWITCH which is connected to the boiler. When the valve is fully open, the boiler is called.

So, the thermostat itself is not operating the boiler. It only operates the zone valve. The zone valve then operates the boiler.

It is quite common for an endswitch to be defective.
 
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Old 10-16-11, 02:04 PM
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Ok I had my fiance turn on the lower zone, which has worked and did work. I heard the whirring noise. I did this zone first to get an idea of the noise and it was easy enough to hear. When we tried the upstairs zone there was no noise what so ever as expected. I think in a couple of days when I have time I am going to clean up the wires and figure which ones go to this zone valve and double check connections.

Otherwise I am going to order this zone valve.
I will make sure its right before I buy it but I think this is the only way to fix the endswitch correct?
 

Last edited by NJT; 11-18-11 at 06:02 PM.
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Old 10-16-11, 03:23 PM
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No... don't order that yet.

If you didn't hear any noise when the thermostat was pushed up, then there is either a problem with the wiring, the thermostat, or possibly the MOTOR in the zone valve.

You can just throw parts at the problem if you want, that's OK... but why not attack logically and possibly save some $$$ ?

The next step would be to set up your multimeter for 24VAC and measure the voltage on the two YELLOW wires going to the UPSTAIRS zone valve. When the thermostat is calling for heat, there should be 24 VAC on those yellow wires, when it is not calling there should be ZERO volts on them.

If you get 24VAC on those yellow wires, then it's probably the motor in the valve head, which can be changed by itself for less money. But then, you still won't know if the endswitch is ALSO bad... it might be, or it might not.

If you do NOT get 24VAC on those yellow wires, then since you've already tested the wiring to the thermostat, you would have to suspect the thermostat itself.

Be vigilant while you are working on this for broken wires inside those wire nuts. Wires can be very sneaky about hiding breaks!
 
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Old 10-16-11, 05:33 PM
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I need to mention one other thing... if your zone valves are old, you might not be able to change the head without draining the system! And if they are that old, you will need an 'adapter kit' in order to install the newer style power heads if you do end up changing it.

You can tell by looking. If there are FOUR screws holding the head in place, you have the old style. If there are TWO screws and TWO locating 'pins', you have the newer style.
 
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Old 10-18-11, 12:15 PM
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Thanks so far! I tested ac voltage and after figuring out which wires were "yellow" I got 24ac when thermostat wires were crossed. Only one of the wires was yellow, but I narrowed it down to get the other wire by completing circuits and I figured it out. As you can probably tell by this the head itself is real old. Probably original as far as I can tell.

With help from Honeywell's site I also determined that because it did not have a sideways 6 next to the model number it is of the old design. So I know already I need the head and the adapter kit.

Now you mentioned I could replace the motor in the valve head, would I be able to actually change out the motor? Or were you talking about the removable head and leaving the actual valve part alone? And what about the end-switch you mentioned? From the schematics I found on the site I do not see how these are removable by themselves. I do agree its better to change only what is necessary. Thank you!

(Don't you wish all companies gave you detailed schematics!)
 
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Old 10-18-11, 08:51 PM
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Only one wire was yellow? That's odd... but I guess if they are that old, then certainly something could have changed. I'm starting to turn more yellow in my old age.

But maybe I made an incorrect assumption... aren't there four wires coming out of each zone valve, two yellow and two red?

Yes, you can change the motor itself. You cut the wires close to the old motor, strip the ends, wire nut the two leads from the new motor back together. If you look inside one you will know exactly what to do.

Let's just hope that after you change the motor, you don't find you need an endswitch also!
 

Last edited by NJT; 11-18-11 at 05:56 PM.
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