Troubleshooting

The Harvest Home App won't load

Confirm the Harvest Pod is powered (see The system is off, or a component has no power) and that its network indicator shows connectivity.
Wait ~5 minutes after any Pod reboot before opening the app.
Make sure your phone/computer is connected to the Pod’s Wi-Fi access point (HarvestPodXXXX, where XXXX is the Harvest Pod S/N — credentials and S/N and are on the label under the Pod).
Use any web browser on the phone or computer and go to harvestpodXXXX.local
Power-cycle the Pod: press the power button (LED turns off), wait 10 seconds, then press it again (LED turns on), and wait ~5 minutes after any Pod reboot before opening the app.

Pod power button (S/N 1300 and later).
If you are still unable to get the Harvest Home app to load, contact Harvest Support (support@harvest-thermal.com or 510-962-6898, options 3, 2).

The system is off, or a component has no power

Confirm power at each component:
- Harvest Pod — power-button LED (underside, left) is on (for Pod S/N < 1300 there is no power-button).
- SANCO2 — red “heartbeat” light at the top-right of the display (indicates power and no internal error).
- Thermostat — display is on; a dead thermostat can indicate the air handler is unpowered.
Check the dedicated breakers — SANCO2 (15 A) and any DX A/C outdoor unit (40 A) — plus the air-handler circuit, and confirm any GFCI outlet hasn’t tripped.
Power-cycle the Pod: press the power button (LED turns off), wait 10 seconds, then press it again (LED turns on). If the button does not light up, the Pod’s breaker may be off or its power supply unplugged.

Harvest Pod power button — Pod power button (S/N 1300 and later).

No heat, but the water is hot

Check the air handler is powered: confirm the thermostat display is on, then set the thermostat to run the fan and check that air comes from the vents. If either check fails, the air handler has no power — check the air-handler breaker and any GFCI outlet.
Check all valves are open — at the Harvest Pod (lines A, B, C, D, E, H) and at the tank (lines F, G, H, and HPH / Heat Pump Hot).
If the air handler is powered, all valves are open, and there is hot water in the tank, there may be an air lock in the Harvest Pod circulator pump. Purge the heating loop:
- Close the shut-off valve on the service valve on line H.
  - Open the service valve hose bib (HB) drain for at least 5 minutes, until no air is visible in the water.
  - Close the drain and re-open the service valve on line H.

Hot water is not hot enough

Run hot water for about 5 minutes, then check the delivered temperature in the Harvest Home App under Advanced System Setup > System Checks > Sensor Check > Pod > T-DHW to see what temperature is reached. It should be factory-set to about 120 °F.
If a higher temperature is needed, adjust the thermostatic mixing valve (TMV) to increase it — do not exceed 130 °F to avoid scalding risk. Note that the higher the temperature, the less efficient the system and the higher the energy bills.
TMV failure: if turning the knob doesn’t change the delivered temperature, the TMV may have failed — contact your contractor, or contact Harvest Support (support@harvest-thermal.com or 510-962-6898, options 3, 2) for a spare part to replace it yourself.

Adjusting the thermostatic mixing valve (TMV).

Not enough heat — slow reheat, or the room never reaches setpoint

Common causes, mostly related to thermostat settings:

Night/Sleep temperature not lowered: set the Night temperature at least 2 °F below the daytime temperature.
Night or Away temperature too low: it should be no more than 3 °F below the daytime temperature.
Home temperature too high: setting the thermostat above 72 °F increases the heating load and can make heating slow.
Windows or doors left open while calling for heat — this drains the thermal battery. Allow a couple of hours to recharge after they’re closed.
Home left unheated for several days: it can take up to 24 hours to reheat a cold home. Set an Away temperature no more than ~2 °F below daytime, or begin reheating ~24 hours before returning.
High hot-water use (e.g. filling a bathtub) can pause heating for up to 30 minutes while the heat pump recharges the thermal battery.

Tank temperature sensor (T-TNK) reads below 120 °F after a full charge (heat pump stopped)

Ensure the tank temperature sensor is fully inserted into the back of the thermowell, and use a plug of insulating material to reduce thermal losses and prevent tension on the wire from pulling the sensor out.

Do NOT use a clip to secure the sensor — it can cut into the wire insulation and create an electrical short.
Ensure the tank temperature sensor wire is not being crushed by the metal clip at the tank thermowell (specific to the SANCO2 119G tank). If it looks at all damaged, repair damaged section with electrical tape.
The T-TNK connector can be uplugged at the pod, and then the resistance of the T-TNK connectcor can be measured directly. It will range from ~2-3 kOhm if close to 145F, down to about 15 kOhm if at room temperature if it is working correctly. If it is showing an open connection, or a short, it should be replaced.

The SANCO2 heat pump does not turn on

Check that the heat pump is powered on (red dot blinking on the display).
Check for error codes — see The SANCO2 shows an error code
Check that the tank is not already full. The heat pump will not run if the tank is full.
- The Harvest Home App shows the state of charge, and the T-TNK temperature.
- Feel the PRV valve on the tank to see if it is hot.
Use the System Setup > System Checks page of the Harvest Home App to run a Hydronic Test > HPWH Test, which will force the heat pump to turn on.
Check that all isolation valves are open.
Thoroughly purge the heat pump from all three purge valves (cold line, hot line, and the circulator-pump valve underneath the unit).
Ensure there is no debris obstructing air flow around the heat pump.
Ensure no spring check vavle exists on the plumbing lines going to the SANCO2 heat pump.
Check that all wiring connections are good at the heat pump and the Pod.
If the SANCO2 is still not turning on, contact Harvest Support (support@harvest-thermal.com or 510-962-6898, options 3, 2).

The SANCO2 shows an error code

An error code on the SANCO2 display is one letter + one digit.

E9 — possible air lock in the SANCO2 circulator pump. Purge the SANCO2: open the bleed valve underneath the unit, bleed at high flow for at least 5 minutes (until no air is visible in the water), then close it.

SANCO2 bleed valve location (underneath the unit).
H7 — wiring error with the tank temperature sensor:
- Check all temperature-sensor connections.
- Check for cuts, defects, or rodent damage to the Cat5 cable between the Pod and the SANCO2.
- Check the wiring at terminals 1 & 2 in the SANCO2 signal box.
For the full list of codes and detailed procedures, see the SANCO2 GS4 & GS5 Troubleshooting & Maintenance guide (PDF).

Chemical or acrid smell in the water

From the SANCO2 GS4 Installation Manual — if bond or flux has entered the tank and the hot water has a chemical/acrid smell:

After heating the water in the tank, drain it and clean inside the tank. Fill with 26 gallons of water and exchange twice.
Fill up the tank.
Drain water from the relief valve for one to two minutes.
Run water from all hot-water faucets in the house for about ten minutes to clean the pipes.

Descaling

In hard-water areas, mineral scale can build up over time and reduce hot-water performance. The system may need periodic descaling. See the Descaling guide for the full procedure.

Issues with other units in the system (air handler, A/C, heat pump water heater, tank)

For issues relating to (or warranty on) individual units within the system — such as the air handler, air-conditioner heat pump, heat pump water heater, or hot water tank — refer to the manufacturer’s documentation and/or website for guidance.