Yes, in most cases you can replace the rubber anti-vibration feet (also called anti-vibration mounts or isolation pads) on your outdoor heat pump unit yourself — no licence is required for this task. It's a simple mechanical job that doesn't involve touching any refrigerant lines, electrical wiring, or gas connections, so it sits well within what a capable NZ homeowner can tackle safely on a weekend.
Why Anti-Vibration Feet Matter
The rubber feet sit between your outdoor unit (the condenser/compressor unit) and whatever surface it rests on — a concrete pad, a wall bracket, or a roof mount. Over time, UV exposure, weather, and constant vibration cause the rubber to harden, crack, or compress flat. When that happens:
- Noise and vibration transfer into the structure of your home, which can be particularly annoying if the unit is near a bedroom wall.
- The unit may no longer sit level, which can affect drainage and, in some cases, compressor lubrication.
- Worn mounts can gradually allow the unit to shift, putting stress on refrigerant pipework connections.
Replacing them promptly is good preventive maintenance and can noticeably reduce operating noise.
What You'll Need
Before you start, gather the following:
| Item | Notes |
|---|---|
| Replacement anti-vibration feet/pads | Match the bolt hole diameter and load rating to your unit |
| Adjustable spanner or socket set | Metric sizes — most units use M8 or M10 bolts |
| Spirit level | To check the unit is level after reinstallation |
| Gloves and safety glasses | Basic PPE |
| Torch or head lamp | Useful if working in a shaded area |
Replacement rubber feet are widely available at Bunnings and Mitre 10, or through HVAC trade suppliers. Check your unit's installation manual for the correct size and load rating — this information is often printed on a label inside the front panel of the outdoor unit. If you can't find it, search the model number online or contact the manufacturer's NZ distributor.
Step-by-Step: Replacing the Feet
1. Turn the Unit Off
Switch the heat pump off at the indoor controller and then at the isolating switch on the wall near the outdoor unit. You do not need to isolate the unit at the switchboard for this job, but turning it off at the local isolator is good practice and keeps you safe. Do not attempt to disconnect any wiring or refrigerant lines — that is restricted work.
2. Assess the Existing Feet
Have a look at how the existing feet are attached. Most outdoor units sit on four rubber feet that bolt through a base frame. Some are simple threaded studs; others use a bolt-through arrangement. Take a photo before you start so you have a reference.
3. Support the Unit
Outdoor units can weigh anywhere from around 30 kg to over 80 kg depending on the model. Do not attempt to lift the unit alone. Get a helper. Use a trolley jack or timber offcuts to temporarily support the base while you swap each foot — work one corner at a time so the unit is never unsupported.
4. Remove and Replace Each Foot
Unbolt the old foot, note the orientation, and fit the new one. Hand-tighten first, then snug up with a spanner — don't overtighten or you'll compress the rubber and defeat the purpose of the mount.
5. Check Level and Clearances
Once all four feet are replaced, use your spirit level to confirm the unit is sitting level (or very slightly tilted toward the drain outlet if your model requires it — check the manual). Also confirm the unit still has adequate clearance around it for airflow as specified by the manufacturer.
6. Restore Power and Test
Turn the isolator back on, run the unit, and listen. You should notice a reduction in vibration noise almost immediately if worn feet were the culprit.
NZ-Specific Considerations
- NZ climate: In coastal or high-UV areas, rubber degrades faster. Consider UV-stabilised or neoprene mounts for longer life.
- Building Code compliance: The outdoor unit installation must continue to comply with NZ Building Code requirements — particularly around clearances and weathertightness of any penetrations. Replacing feet doesn't affect this, but don't reposition the unit in a way that reduces required clearances.
- Healthy Homes Standards: If you're a landlord, a well-maintained heat pump is part of your heating obligations under the Healthy Homes Standards. Keeping the outdoor unit in good condition supports reliable heating performance.
- Warranty: Check your heat pump warranty before doing any maintenance. Most manufacturers allow owner maintenance of non-refrigerant components, but it's worth confirming.
When to Call a Professional
While replacing anti-vibration feet is DIY-friendly, call a licensed heat pump installer or HVAC technician if:
- You notice refrigerant line connections are loose, oily, or corroded near the base of the unit — this could indicate a refrigerant leak, which must only be handled by a licensed refrigeration technician under the relevant regulations.
- The isolating switch or wiring near the unit looks damaged — electrical work is restricted and must be done by a registered electrician.
- The unit is mounted on a wall bracket or roof and working at height safely is beyond your comfort level.
- The base frame of the unit itself is cracked or corroded and needs structural assessment.
- You're unsure of the correct replacement specification for your model.
You can find qualified local heat pump installers and HVAC technicians on tradedirectory.co.nz.
ISO 9001
