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System 2000 heat going to heating zone when hot water zone is calling for heat

jkupiecjkupiec Member Posts: 6
Hi all. I have a System2000 model EK-1f. I noticed a while back that when the hot water zone is calling for heat, looking at the control panel light, the hot water and zone 1 heat output lights come on and heat is actually thrown to zone 1 also. The reason I noticed this is I got heat in the zone 1 rooms in the middle of summer. I removed the thrermostat that controls zone 1 to make sure it was not a thermostat issue in zone 1. I have 4 heating zones total. Even worse, after the hot water zone light turns off and the hot water tank is fully satisfied from a temperature standpoint, that zones output light goes off but the zone 1 output light stays on and continues to dump heat into zone one until all the heat is dumped from the boiler. Is this normal that zone one becomes the final dumping point of heat. A picture of the System2000 controller panel is attached.

Thanks ahead for your help


  • HVACNUTHVACNUT Member Posts: 3,282
    The zone 1 zone valve is getting 24v from the Manager so its always open allowing heat to circulate on a domestic call. Check the lever on the zone valve. It probably moves freely when is shouldn't without a heat demand. The issue is in the controls behind the Manager. You'll need a pro but in the meantime you can remove the wire at the #1 terminal on the right side of the Manager. That will close the zone valve until the repair is done.
  • jkupiecjkupiec Member Posts: 6
    Thanks HVACNUT, I did what you said and it makes sense. My pro is coming in two weeks to clean my boiler. Do you think the problem is with my zone valve. I don't have the thermostat connected.

  • jkupiecjkupiec Member Posts: 6
    Or could the problem be with the system 2000 control card. My boiler is about 10 years old.
  • szwedjszwedj Member Posts: 20
    If when you disconnected the wire to the zone valve on Z1 terminal, the zone 1 output light on the right went out, it’s most likely a bad zone valve motor. If the output stayed on with the zone valve disconnected it’s most likely a bad output on the system manager. All this assuming you still have the thermostat disconnected on the left side terminal T1.
    Joe Szwed
    Energy Kinetics
  • jkupiecjkupiec Member Posts: 6
    Happen to check to the boiler when the hot water tank was calling for heat. After the tank was satisfied the zone #1 light was still on. I took off the wire on Z1, before hot water tank called for heat. The Z1 light stayed after the lights went out for the hot water zone. The circulator pump is still running but now the zone #1 is zone valve is closed. Will this hurt the circulator pump as all the zones are closed. See the picture below to see the lights.
  • jkupiecjkupiec Member Posts: 6
    Yes the thermstat was removed on T1
  • HVACNUTHVACNUT Member Posts: 3,282
    No it wont hurt the circulator. It actually runs that way at the start of almost every cycle. Theres a 1/2" bypass pipe going into the back of the boiler. After a heat or hot water demand ends, the circulator will continue to run for a preset time, as set by the dip switches.
    So the problem is in the Manager or a control relay behind it.
  • szwedjszwedj Member Posts: 20
    If you look at the picture, it looks like it's doing a normal post purge to zone one. The boiler is still fairly hot and the system circ is running. If you reset power using the system switch on the left, as long as there are no heat calls the outputs on the right should go out.
    Joe Szwed
    Energy Kinetics
  • jkupiecjkupiec Member Posts: 6
    Thanks to both of you. Does the hot water zone normally purge to the hot water tank after the tank temperature has been satisfied. BTW this whole cycle described above happens ever time I see the hot water zone calling for heat. I just disconnected the right side zone 1 wire be note above so heat does not get sent to zone 1 right now as its summer.
  • szwedjszwedj Member Posts: 20
    edited August 2019
    Yes, the system will post purge to the hot water tank for a maximum of 5 minutes. Heating zones can post purge for up to 20 minutes. BTW, does your system have a plate heat exchanger for the domestic hot water? The reason I ask is based on the first picture you posted, the domestic side of the plate may need to be back flushed. You can see during the hot water call, the return temp climbed enough to shut the burner off. That is typical of a flow restriction on the domestic side of the plate. You might want to have your service tech check it out.
    Joe Szwed
    Energy Kinetics
  • RogerRoger Member Posts: 112
    Thank you for your comments and posts.

    Here is a link to manager diagnostics:

    The output light on as you describe (not when actively heating or purging) is often caused from a short in that output. It could be from crossed wires or a failed zone valve. The diagnostic shows how to test by removing the output quick connector.

    If you only had 3 heating zones, you could have moved the zone valve and thermostat to an unused zone.
    If it turns out that the manager output is damaged, you will be eligible for a core return credit - see replacement manager costs here:

    I would suggest waiting for your heat pro to test the zone valve, wiring, and output.

    Energy Kinetics, Inc.
    Erin Holohan HaskellCanucker
  • br2kxlbr2kxl Member Posts: 2
    Wanted to continue this thread, I also have a system 2000 that is bringing heat through the baseboards when there is a demand for hot water. I don't have any of the lights coming on in the heating zones though, just the hot water lights. 3 zones, with two of the pipes hot, seems to be passing through the radiator on one zone. Heating person came and told us to change out the two nest thermostats that were effecting the two zones, the zone that wasn't effected didn't have nest. Changed the nests, but still seem to have problems, any ideas ?
  • SuperTechSuperTech Member Posts: 1,306
    edited 11:16AM
    @br2kxl hope you changed the Nests to any other thermostat. The first thing you want to look at is the zone valves for that zone. Does the lever on the valve move back and forth freely? Check the way it operates and compare it to the other zone valves that are working. You also need to see what the energy manager is doing while the malfunction is happening. Take pictures if possible. There is a lot good information on how to resolve this problem in this thread.
  • br2kxlbr2kxl Member Posts: 2
    I take it you are not a big fan of the nest. I will take a picture, the heating person did check the zone valves, said they were fine.
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