Radiant Zone Issue

H20Boy

Hi everyone; I am trying to troubleshoot an issue with my radiant heating system and I have not had much luck....thought I would ask some pros.

The system has two zones but one has not been working (Circulation pump not running and boiler not starting when thermostat calls for heat)

I have tried a few things as far as trouble shooting goes; here are some of them.

1. Tried a known working thermostat on the dead zone with no luck
2. Transferred control wires/circulation pump wires to different zone on control board with no luck
3. Tried a known working relay with no luck
4. Have tested for power on zone control valve (Automag RI series) has 24v power going to power terminal on one unit and is jumper-ed to second valve (both have 24v and green light is on). There is also 24v on thermostat terminal on valve. And finally there is 24v from valve terminal to the control relay box.

When heat is called for on thermostat I hear the valve open and "red" light turns on. I assume that if this red light turns on it means that the end switch has also been switched?

5. There is also 120v at the line power side of the relay control board.

Any help would be great; I am sure that I'm over looking something.

Ironman

How about posting some pics of your setup?

hot_rod

Typically the thermostat sends a heat call to the relay box, the relay triggers a pump and a call for heat to the boiler.

If the relay lights come on when the thermostat calls, you should be fine, often you hear a relay click when the valve opens, that powers the pump and closes a signal to fire the boiler.

Does the pump get 120V? if so you could have a stuck or defective pump, or an air lock in the loop if the pump powers and spins.

Has the Automag valve been changed recently? Some of those are power close valves, maybe the wrong valve has been installed?

H20Boy

Thanks for the responses guys. I will get some pics of the set up later on tonight when I am at the house.

And the relay board does not light up on this zone... I guess the one thing I havnt tried is checking the pump output for 120v .... I assumed that since the lights werent on at the relay board that the relay had not pulled in and closed the pump loop. Will try that though and get back to ya. Thanks!

H20Boy

So here is a few photos of the set up. As picture was taken zone 1...which is currently working is in operation

rick in Alaska

Looks like zone one is a priority zone on that control. And, the priority light is currently on. So, I am assuming the bad zone is zone 2? If so, turn off the priority zone with the switch on the right side of the control and see what happens.
Rick

H20Boy

Hmmm...it's funny you say that. I didn't notice that the priority light is on... but the switch is in the off position *scratches head

todd_ecr

The priority LED will come on whenever Zone 1 is calling regardless if the priority switch is on or not.

Easy way to test the control: Jump out the Tw-Tr terminals. Does it activate the circulator? If it does, the issue is outside the Argo control, if it doesn't, the issue is in the control.

todd_ecr

Now that I look closer, I think we can eliminate an external issue. Is the ZR-ZC jumper in place and are the screws tight? Can you slightly apply pressure to that relay?(second one in from the left)

H20Boy

^ Will give both of those options a go. Thanks again! And I will keep everyone posted

todd_ecr

One other note, the 3 zone(pump) relays and the X-X relay are the same and are interchangeable. Zone 3 looks like an unused zone, so that one could removed and used in the place of the X-X. That could tell you if it's a bad relay. We do have replacement relays available.

H20Boy

Hey guys... I jumped out tw - tr on zone 2 and it fired right up... I'm going to assume that maybe the end switch is bad? Or maybe the valve just needs a new head? Any thoughts from here?

Thanks again

Ironman

Try jumping "R" and "W" going to the thermostat. If it opens the valve and fires the the boiler, then either the stat or the cable going to it is bad. If not, the the head is bad.
I've also seen the pinch connectors go bad on those heads.