Lennox Heat Pump Installation Instructions

bytechtown

Heat pumps are all the rage these days so you may notice and uptick in service calls to go out and set one up for a new or existing customer. These outdoor HVAC units can seem intimidating at first if you haven’t dealt with one yet, but with the help of these Lennox heat pump installation instructions, you’ll be able to get the job done in no time.

The following steps are applicable to outside heat pump models from Lennox such as the Elite® Series XP16 units.

How to Install

Installing isn't as simple as just taking the unit out of the box and plugging it in, there’s a few things to consider before you even begin to install.

Outdoor Placement Tips

The location of the heat pump is vital for its operation. Consider the following tips when deciding where to install the unit:

Depending on the state and town, there may be sound ordinances based on the unit’s sound level registered from the neighboring property, not from the installation property. Thus, you may have to install the unit as far as possible from the property line.
Don’t install directly next to a window since glass has a very high level of sound transmission.
For installations at ground level where the unit will be placed on a slab, the top of the slab should be high enough above grade so that water from higher ground will not collect around the unit.
For roof mounting units, ensure the unit is a minimum of 6 inches above the roof surface to avoid ice build−up around the unit.

Installing Louvered Panels

Step 1. Position the panel almost parallel with the unit.
Step 2. In a continuous motion, slightly rotate and guide the lip of the top tab inward and then upward into the top slot of the hinge corner post.
Step 3. Rotate the panel to be vertical to fully engage all of the tabs.
Step 4. Hold the panel’s hinged side firmly in place while closing the right-hand side of the panel so the screw holes align.
Step 5. Insert the screws and tighten them once the panel is properly positioned and aligned.

Adding Polyol Ester Oil Requirements

For installing a new line set, you need the steps and considerations for adding Polyol ester oil.

Add oil based on the amount of refrigerant charge in the system.
Systems with 20 pounds or less refrigerant don’t require having oil added.
Systems over 20 pounds should have one ounce for every five pounds of HFC−410A refrigerant added.

Line Set Requirements

Installing horizontal runs – To hang line sets from a joist or rafter, use either metal strapping material or anchored, heavy nylon wire ties.
Installing vertical runs – Insulate liquid lines when it’s routed through areas where the surrounding ambient temperature could become higher than the temperature of the liquid line or when pressure drop is equal to or greater than 20 psig.

Brazing Connections

The following steps are for brazing line set connections to service valves.

Step 1. Cut and debur – Square cut the ends of the refrigerant lines and then debur the ends of them. Never crimp the end of the lines so the pipes are kept round.
Step 2. Cap and core removal – Remove both the service cap and core from both the liquid line service valve and suction/vapor line service valve ports.
Step 3. Attach the manifold gauge – Attach the manifold gauge set for brazing the liquid and suction/vapor line service valves. Flow regulated nitrogen (at 1 to 2 psig) through the low−side refrigeration gauge set into the liquid line service port valve, and out of the suction. Then connect the gauge set low pressure side to the liquid line service valve, and connect the gauge set center port to the bottle of nitrogen with a regulator vapor line service port valve.
- Note: Remove core from valve in suction/vapor line service port to allow nitrogen to escape.
Step 4. Wrap service valves – In order to protect the service valve seals during brazing, you need to wrap dampened cloths around the service valve bodies and copper tube stubs. You can use additional damp cloths under the valve body to protect the base paint.
Step 5. Flow nitrogen – Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration gauge set into the valve stem port connection on the liquid service valve and out of the suction/vapor valve stem port.
Step 6. Braze line set – Wrap both service valves with damp cloths before brazing to line set. Damp cloths must remain moist throughout the brazing and cool−down process.
Step 7. Finish brazing – After all connections have been brazed, disconnect the manifold gauge set from service ports. Apply additional damp cloths to both service valves to cool piping. Once the piping is cool, remove all of the cloths.

Flushing Line Set & Indoor Coil

Flushing is only required when the previous system used HCFC−22 refrigerants. The line set and indoor unit coil must be flushed with at least the same amount of clean refrigerant that previously charged the system.

Step 1. Set the recovery machine for liquid recovery and start it.
Step 2. Open your gauge valves so the recovery machine can pull a vacuum on the existing system line set and indoor unit coil.
Step 3. Invert the cylinder of clean HCFC-22 and open its valve so liquid refrigerant can flow into the system through the vapor line valve.
Step 4. Wait for the refrigerant to pass from the cylinder and through the line set and indoor unit coil before it enters the recovery machine.
Step 5. Once all of the liquid refrigerant has been removed, switch the recovery machine to vapor recovery to ensure all the HCFC-22 vapor is removed from the system.
Step 6. Wait for the recovery machine to pull down to 0 the system.
Step 7. Close the inverted HCFC-22 drum’s valve and the gauge set valves.
Step 8. Pump out any remaining refrigerant out of the recovery machine and then turn it off.

Electrical Connections

For installations in the US and Canada, wiring must conform with current local codes.

Step 1. Size the circuit and install the disconnect switch – Consult the unit’s dataplate for the minimum circuit ampacity and maximum fuse or circuit breaker. Then install power wiring and the properly sized disconnect switch.
Step 2. Install the thermostat – A separately ordered thermostat for inside the home needs to be installed on an interior wall, approximately in the center of the conditioned area and 5 feet from the floor.
Step 3. Low voltage connections – Run the 24VAC control wires through the cutout with a grommet. Then through the wire tie to make the 24VAC control wire connections. Then tighten the wire tie to secure the control wiring.
Step 4. High voltage power supply connections – High voltage wiring will be run through conduit and connected. Be sure to also ground the high voltage connections.

Testing for Refrigerant Leaks

After installing a Lennox heat pump, it’s vital to check for leaks.

Step 1. Connect the cylinder of the HFC-410A refrigerant to the center port of the manifold gauge set while both manifold valves are closed.
Step 2. Open the valve on the HFC-410A cylinder (vapor only).
Step 3. Open the high pressure side of the manifold so HFC-410A can enter the line set and indoor unit and weigh in a trace amount of HFC-410A.
Step 4. Close the HFC-410A cylinder valve and the high pressure side of the manifold gauge set.
Step 5. Disconnect the HFC-410A cylinder.
Step 6. Connect a cylinder of dry nitrogen with a pressure regulating valve to the manifold gauge set’s center port.
Step 7. Adjust the pressure of the dry nitrogen to 150 psig.
Step 8. Open the high side manifold gauge valve to pressurize the line set and the indoor unit.
Step 9. After a few minutes, open one of the service valve ports and check that the refrigerant added to the system is measurable with a leak detector.
Step 10. Once leak testing is finished, disconnect all gauges from the service ports.

Tags: