Damper pump diagnostics. So when you look at the pump, the red wires always need to come out the back side of the pump. Both of your tubes will be connected to the back left and the back right. Back left is always pressure, back right is your vacuum.

You need a minimum of 40 inches of water column for pressure to close dampers on a SpacePak or Unico system. At that level, you can fully close the damper against static pressure. In healthy systems, pressure may be 55–65 inches, with vacuum in a similar range.

Two front ports should remain open on both old and new panels. These connect to a muffler located behind the main circuit board. There is nothing typically required there from a service standpoint.

Solenoids use a plus common terminal along with zone terminals such as zone one, zone two, and zone three. On HeatPumPro systems, the common terminal is shared across solenoids. Zone wiring typically runs from the zone terminal to its corresponding solenoid connection.

AirBoss zone outputs and inputs correspond to the same general structure. A row of green LEDs indicates which zones are active. Zone one, zone two, zone three, and zone four lights will illuminate depending on demand.

There is no dedicated R light on the AirBoss panel, which can cause confusion during troubleshooting. R, Y, and G inputs do not directly map to the panel labeling. Instead, the system logic is closer to W1, Y1, Y2, and G, with heating and cooling calls interpreted differently.

The MPS board uses a display select button to navigate through zones and outputs. Pressing display select cycles through zones, showing either inputs from thermostats or outputs to equipment depending on the mode selected.

For example, selecting Zone 1 shows whether there is an input call from that thermostat. Selecting output mode shows what signals are being sent to equipment. Zone 2 and Zone 3 follow the same diagnostic structure.

Fault indicators appear when a zone has an issue. For example, an F1 fault indicates a problem on Zone 1, often related to missing or incorrect call signals such as Y, W, or G combinations.

On older control logic, a cooling call requires both Y and G. Y alone would only energize the outdoor unit, potentially leaving the blower off. Modern equipment may behave differently, but most panel logic still assumes Y + G for cooling.

If only Y is energized on a zone expecting both Y and G, the system may register an F2 fault due to incomplete call logic.

Relay testing is best performed using an ohm meter rather than relying solely on audible continuity. A meter beep may still register continuity even if resistance is too high for a good relay.

A good relay should read under 1 ohm. Readings above that range, such as 3 to 5 ohms, indicate a failing relay even if continuity is still present.

For testing, meter leads can be inserted into designated test ports or carefully placed behind terminal tabs to contact metal points directly.

Damper diagnostics rely on pressure and vacuum readings. At zero inches of water column, dampers remain in a relaxed open state. Pressure is required to close them.

At 40 inches of water column or higher, dampers should fully close. At around 35 inches or higher, they should begin opening depending on system design and calibration.

When testing, a negative or low reading indicates that a zone is actively calling, since vacuum is required for certain damper states and pressure is used for closure.

If pressure readings are low when teed into a line, it may indicate leaks in dampers or tubing, or physical damage such as punctures or staples in the line.

Isolating sections of tubing by pinching lines can help identify leaks. If pressure increases when a section is pinched, the leak is likely downstream of that point.

By progressively isolating halves of a system, technicians can narrow down which dampers are faulty by observing changes in pressure response.

Warranty procedures require contacting support when failures occur. This allows real-time diagnostic tracking and helps identify systemic issues more quickly than waiting for returned parts.

Providing a serial number is required for warranty validation. This helps confirm production batch, system age, and eligibility for coverage.

Technicians are encouraged to call from the job site when possible so failures can be verified in real time and properly documented.

Once validated, replacement parts are issued directly without extensive paperwork or claims processes. The failed part is simply replaced in the field.