Air-to-Water Heat Pump Installation Guide | APOLLO

Is APOLLO heat pump installation difficult?

The outdoor unit is only one part of the job. APOLLO produces heated or chilled water, but the system performance depends on how that water is circulated, protected, controlled, and delivered inside the building.

A simple heating-only setup is different from a full project with radiant floors, fan coils, domestic hot water, backup heat, multiple zones, and cooling. That is why the important work starts before installation: sizing the heat pump, choosing the indoor distribution, planning tanks and pumps, and confirming who will design and install the hydronic system.

Before equipment is ordered, the project should answer:

• What heat pump size fits the load?
• Where will the outdoor unit sit for airflow, snow clearance, drainage, and service?
• Will the system use radiant floors, fan coils, an air handler, domestic hot water, or a combination?
• What tanks, pumps, glycol protection, controls, and backup heat are required?
• Should the Hydro Smart Station be included from the beginning?

When these decisions are made early, the installation is cleaner, easier to service, and less likely to need changes after equipment is on site.

Choose the right outdoor unit location

The outdoor unit location affects performance, serviceability, sound, drainage, and winter operation. The unit should be installed where it has strong airflow into and out of the heat pump. It should not be blocked by walls, fences, garbage, stored materials, snow, or anything that restricts ventilation.

A good location should provide:

• Clear airflow around the outdoor unit.
• Enough space for maintenance and servicing.
• Protection from heavy snow accumulation.
• Proper condensate drainage.
• A stable, load-bearing base.
• Reduced vibration transfer using proper mounting and rubber pads where appropriate.
• Good neighbor placement so discharge air does not blow directly toward a fence or nearby property.
• Safe surroundings away from oil, garbage, and flammable materials.

In cold climates, the base should be high enough to stay above average snow accumulation. Proper clearance helps the heat pump breathe, drain, defrost, and operate more reliably through winter.

Plan the hydronic layout before installation

The APOLLO heat pump connects to a water-based distribution system. This is where many installation problems start if the project is not planned before equipment is purchased.

Confirm the full hydronic plan early:

• Indoor distribution: radiant floor heating, fan coil units, central air handler, or another hydronic emitter.
• System loads: space heating, cooling, domestic hot water, pool heating, or multiple applications.
• Hydronic requirements: water temperature, flow rate, pumps, valves, buffer tank, expansion tank, and number of zones.
• Freeze protection: glycol requirements, outdoor piping protection, insulation, and service strategy.
• Controls: thermostats, temperature sensors, backup heat logic, and how the system will be started and maintained.

Radiant floors can be an excellent match because they often use lower water temperatures. Fan coils and hydronic air handlers are useful when the project also needs cooling or faster room response. Domestic hot water planning requires the correct tank, heat exchanger strategy, controls, and backup approach.

Plan tanks, glycol, wiring, sensors, and condensate

The detailed installation work belongs in the APOLLO manual and local code review, but these items should still be considered before purchase because they affect equipment selection, mechanical-room space, and installation cost.

• Buffer and DHW tanks: confirm tank requirements, service access, expansion control, air removal, and whether a domestic hot water tank is part of the system.
• Glycol and freeze protection: outdoor piping and exposed hydronic components must be protected against freezing, especially in cold climates.
• Pipe insulation: outdoor piping should be protected from heat loss and freezing, while cooling applications need insulation that helps prevent condensation.
• Electrical and controls: electrical supply, disconnects, backup heat, pumps, valves, and controller wiring must be planned by qualified professionals.
• Temperature sensors: sensor placement affects system control, so installers should follow the official APOLLO manual rather than guessing.
• Condensate drainage: outdoor defrost drainage and indoor fan coil drainage must be planned so water does not create ice, pooling, or moisture problems.

The Hydro Smart Station helps reduce complexity here because it organizes many of the pumps, valves, controls, DHW integration, backup heat, glycol pressurization, and service components in one station.

Plan startup testing and yearly maintenance

Startup should confirm that the full APOLLO system is ready for regular operation. This includes the heat pump, hydronic loop, tanks, pumps, controls, valves, safety devices, and indoor distribution.

A proper startup should verify:

• Water pressure and glycol protection.
• Flow through the heat pump and hydronic loop.
• Leaks at fittings, tanks, pumps, and valves.
• Air removal and proper purging.
• Outdoor unit airflow and drainage.
• Fan coil or radiant floor operation.
• DHW operation if connected.
• Backup heater function if the Hydro Smart Station is used.
• Control settings and temperature sensor readings.

Yearly maintenance should also be part of the plan. A well-maintained system is easier to troubleshoot and more likely to keep its efficiency and reliability over time.

Maintenance may include:

• Inspecting the outdoor unit and clearing debris.
• Checking airflow around the heat pump.
• Checking glycol concentration and system pressure.
• Inspecting pumps, valves, strainers, and fittings.
• Checking condensate drainage.
• Verifying controls and sensors.
• Inspecting electrical connections.
• Cleaning or servicing fan coil units where applicable.

The Hydro Smart Station also helps with serviceability because it combines many system components into one organized location. That makes it easier for installers and service technicians to understand the system layout.

Common installation mistakes to avoid

A high-performance heat pump can only perform well when the full system is installed correctly. Many problems come from layout, sizing, piping, or control mistakes rather than the heat pump itself.

Avoid these common installation errors:

• Installing the outdoor unit where airflow is restricted.
• Placing the unit too low in a snowy climate.
• Forgetting proper condensate drainage.
• Using poor pipe insulation, especially for cooling applications.
• Not planning the buffer tank, DHW tank, or expansion tank correctly.
• Skipping glycol protection in freezing conditions.
• Undersizing or oversizing the heat pump.
• Using the wrong indoor distribution for the required water temperature.
• Installing controls or sensors in the wrong location.
• Building a complicated mechanical room layout when an integrated Hydro Smart Station could simplify the system.

Final recommendation: plan the full APOLLO heat pump system

Installing an APOLLO air-to-water heat pump is about more than placing an outdoor unit. The best results come from planning the full hydronic system: outdoor location, piping, insulation, glycol, tanks, pumps, controls, indoor distribution, and maintenance access.

For many projects, the APOLLO Hydro Smart Station is the easiest way to simplify installation. By integrating backup heating, glycol pressurization, pumps, valves, DHW heat exchanger, controls, and service-friendly components, it can make the installation up to 70% easier and less costly compared with building the hydronic layout from separate components.

If you are planning a new APOLLO system, use this article as a pre-purchase planning guide, then use the official manual and qualified installers for the final installation details.