Digital panel (dxpl02) not relaying instructions/signal to Lifebreath dcs 300

[Nick L]

I have a Lifebreath DCS 300 with the digital panel dxpl02. The lifebreath unit works perfectly and the digital panel appears to function, but selections on the digital panel do not relay to the lifebreath unit. No matter what option I chose or what I press, the lifebreath unit does not respond, even though the digital panel itself reflects the changes.

All 3 bathroom fan controls work. It's only the main digital panel that doesn't do anything.

There seems to be 4 wires available but the digital panel only has 3 wires. The 4th wire is not connected to the Lifebreath or the digital panel.

We have replaced the digital panel and the issue persists.

Thank you,
-Nick

[Admin]

Are the wires connected at the HRV?  Sometimes they break and it's hard to tell without pulling on them.  The wiring itself could be damaged and a continuity test would rule it out.

Which terminals are the bathroom timers connected to and which terminals is the main control connected to?

[Nick L]

Hi, thank you for your suggestions.

We have continuity.

I checked all connections. One bathroom fan control seems to have burnt the ends of all 3 cables. I cut these back to bare copper and reconnected. One copper wire at the main digital panel appears to have been weak and broke off when pulled on. This was fixed and reconnected.

Somehow, we seem to be back to square one. All bathroom controls work and the main digital control turns on but the buttons don't seem to send any signal to the HrV despite changes appearing on the digital panel display. Details displayed are also inconsistent with HRV operation. For example, when the bathroom fan timer is set, it does not reflect on the main digital panel.

[Nick L]

See attached images of HRV unit and connections, main digital control panel connections, bathroom timer connections and digital panel display.

[Nick L]

I have now tried switching a bathroom timer control with the main digital control. The timer fan control turns on and off the HRV at the digital control's original connection, but the digital control does not work when connected in the bathroom. It still turns on and displays everything, and buttons are responsive as far as the display is concerned.

It seems the HRV does not respond to the digital control panel's instructions even though the connections are good.

[Nick L]

What control panel is compatible with a 4 wire HRV connection? It seems there may have originally been 4 wires at source for the main control panel (one is disconnected - see IMG_3387), but there doesn't seem to be any 4 wire control panels for purchase anywhere.

[Admin]

You won't have much luck finding a replacement Programmable Ventilation Controller (PVC) Part # 99-105.  It uses the RED ORG GRN YLW terminals.  I don't think the 3 wire main controls will work with the 300DCS.

Do you have a heating and cooling system and a thermostat close to the HRV main control?  You could use an Ecobee to control everything.

[Nick L]

I do have a thermostat right next to the main HRV control. I understand the Ecobee does limit the HRV functionality, such as single fan speed. Does the Ecobee allow for the 4 wire connection?

How do you check if the HRV unit can recirculate? I understand not all can, but it seems the 300DCS should.

Thank you so much for your support.

[Admin]

You can get the Ecobee with a PEK adapter and use 4 wires.

Another option is turning the thermostat fan on for recirculation and only use the HRV to ventilate.

[Nick L]

It seems the result is the same with or without the PEK adapter. After troubleshooting with Ecobee support, they concluded insufficient power is going to the Ecobee. They say the device needs 24 volts. My multimeter seems to read 15 volts.

Ecobee support also mentioned they did not think this setup could also accommodate the thermostat as the HRV uses up a connection which the thermostat would also require. The thermostat has red and white. The Ecobee has a second white but the red is would be in use by the HRV, assuming we can get it to work.

This seems unusually obscure for a less than 20y old unit.

We somewhat had to guess at the PEK connections to the HRV as there was no clear direction on what Color cable to connect into Orange for example. We know the power comes from Green and connected the PEK's C to Green.

Thank you so much for your support.

[Nick L]

After further trial and error, I disconnected the Orange terminal at the HRV unit and connected Black instead. Now the Ecobee turns on but does not appear to send a signal to the HRV, and the Ecobee screen says N/A for "heat value" after the setup is complete.

Is there a diagram or legend that explains each HRV terminal color and their purpose? I'm unclear on why they are not all being used, and ecobee support and our local tech don't seem to have any answers. Which HRV terminals (Yellow, Green, Orange, Red, Black) connect to which display terminals? There are only 4 wires as we have already established. The green seems to provide power; what are the others for?

The issue must lie in these connections.

Now, an hour after typing this, the ecobee screen is saying: detected terminal voltages are too low. Ensure all wires are in the correct terminals and firmly attached.

I've checked and all are firmly attached. Cannot say for sure that the wires are in the correct terminals.

Thanks again.

[Nick L]

[...]and the PEK adapter was removed. It seemed to offer no value here since there is power going to the display.

[Admin]

It sounds like you're powering the Ecobee with the HRV, which won't work.

I was suggesting you replace both thermostat and HRV control with the Ecobee.  You need to power the RC terminal with 24V from the furnace which is usually the red wire.  You need 6 wires to make this work with a PEK adapter and you have more than 6 wires behind your thermostat and HRV control.  You probably have at least 7 wires and don't need to use the PEK adapter.

The Ecobee, as far as controlling the HRV goes, is just a set of dry contacts.  You would connect the HRV R and G terminals to the Ecobee ACC terminals.  Connect one wire to ACC+ and the other wire to ACC-, and it does not matter which one goes where. You change the Ecobee settings and add the HRV.

If you don't want to change your thermostat you would have to steal 24V from the furnace or install another 24V transformer somewhere you can tie into the existing HRV control wiring.  First disconnect the 4 main control wires from the HRV.  You would connect 2 of the HRV control wires to the new transformer and connect them to RC and C on the Ecobee.  You could buy a plug-in transformer and plug it in next to the HRV and may have to extend the 2 wires a little.  Then connect the last 2 HRV control wires to R and G on the HRV, and the other end connects to the Ecobee ACC terminals.