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The Healthy Homes Standards introduced a range of appliances into NZ rental properties that many landlords and property managers hadn't previously had to think about. Heat pumps, bathroom extractor fans, and kitchen rangehoods are now standard in properties where in many cases they didn't exist before. Many landlords have also installed whole-house ventilation systems like DVS, HRV, and SmartVent over the same period to help manage moisture and condensation.
These systems need ongoing maintenance to keep working properly, and most routine inspection processes weren't set up with these systems in mind.
This guide is a practical reference for property managers and landlords. It covers what to check on each system type at a routine inspection, what signals that something needs professional attention, and how to build a simple annual maintenance routine around each property. Each check takes under two minutes, requires no tools, and requires no ceiling access.
The Healthy Homes Standards require that heating and extraction systems installed to meet the standards, heat pumps, bathroom extractor fans, and kitchen rangehoods, stay in good working order throughout a tenancy.
Whole-house ventilation systems like DVS, HRV, and SmartVent are not required under the Healthy Homes Standards. Where landlords have chosen to install them, the same maintenance principles apply: they need regular servicing to keep doing their job.
The maintenance responsibility is split. Tenants are expected to clean accessible filters on wall-mounted heat pumps and on kitchen rangehoods where the filter mesh is easy to reach. Everything that requires tools, technical knowledge, or ceiling access generally sits with the landlord. For most systems, that's most of the maintenance picture.
Many of the heat pumps and extraction fans installed during the compliance period are now three to five years old. A number haven't been professionally serviced since they went in. The checks below are a practical way to stay across what's in each property between annual service visits.
Changeover is when the gap tends to show up most clearly. A property gets a thorough clean at the end of a tenancy, surfaces, bathrooms, carpets. The heat pump typically doesn't get the same attention. An incoming tenant inherits whatever built up during the previous tenancy: filter accumulation, dust on the fan blades, and in some cases mould on the internal housing. A changeover service before a new tenancy begins is the cleanest way to start fresh.
Start with the filter. The front panel on a wall-mounted unit hinges upward, usually by pressing in at both sides and lifting. Slide the filters out. A filter that's lightly dusty and intact is fine. A filter that's heavily clogged with debris, has a collapsed frame, or has holes in the mesh needs attention. A missing filter means the unit has been running without one.
With the filters back in place, turn the unit on at its lowest fan speed. This opens the louvres at the bottom of the unit. Shine a phone torch up through the louvres. You're looking at the fan housing and the blade assembly. Grey or black spotting on the white housing is mould. Heavy dust on the fan blades is also worth noting. The article on mould in a rental property heat pump covers what that build-up looks like and what removing it involves.
While the unit is running, listen for anything unusual. Grinding, rattling, or whirring sounds that weren't there before are worth noting. They're often early signs that something inside the unit needs attention.
One thing worth passing on to tenants at the start of a tenancy: run the heat pump in heating or cooling mode, not auto. Auto mode cycles between the two to maintain a set temperature. On days with fluctuating temperatures, that cycling creates the moisture conditions where mould establishes inside the unit. It's a simple instruction that makes a real difference over time.
Check the outdoor unit. Vegetation pressing against the sides, long grass at the base, or objects leaning against it all restrict the airflow the unit needs to operate. A clear 150mm at the back and 500mm on the fan side is what's required. Anything sitting on top of the unit, or blocking the top panel where air exhausts, is worth clearing before the next tenancy.
You won't see the internal components of a ducted system during a routine inspection. What you can check is how the system delivers air.
Find the return air grille, usually a larger rectangular grille in the hallway ceiling. You'll need a step stool or small ladder to reach it. There will be a single bolt at one end. Unscrew it and the grille hinges down. The filter sits in a rectangular or square aluminium frame that pulls out of the housing. Check its condition. A heavily loaded filter restricts the airflow the whole system runs on.
Walk each room and check the supply vents in the ceiling. They should all be open and dust-free. Vents that tenants have manually closed off restrict airflow to those rooms and put extra load on the rest of the system.
Run the system and confirm air is coming from all supply vents. A room with no airflow from a functioning system is worth flagging for a technician. While the system is running, listen at the return air grille and at each supply vent. Rattling, grinding, or an unusual change in airflow noise can indicate a developing issue with the duct system or the air handler.
Check the outdoor unit using the same approach as a wall-mounted unit: clearance, vegetation, and debris.
The tissue test is the standard check. Switch the fan on. Hold a square of toilet paper flat against the grille and release it. If the fan holds the tissue against the grille, it's generating enough suction. If the tissue falls, the unit needs attention.
While you're there, look at the grille. Heavy dust and lint on the surface reduces airflow before air even reaches the fan. A grille that's visibly clogged is a good indication the unit is due for a service. A fan producing rattling or grinding sounds is also worth noting. That's often a sign the housing needs cleaning or the motor is wearing.
Switch the rangehood on and check that you can feel air being drawn upward from the cooktop surface. The extraction on a working rangehood is noticeable even at low speed.
Pull out the filter mesh. On most rangehoods it slides or clips out without tools. Cleaning the filter mesh is a tenant responsibility where it's accessible, so it's worth raising at the start of each tenancy if the incoming tenant hasn't been shown how. A filter that's dark with grease and cooking residue is restricting airflow. It's also a fire risk. This is the most visible maintenance item in a rental kitchen and the one most commonly left for the next tenancy to inherit.
These extract from the room rather than directly above the cooktop. The tissue test applies here. Switch the fan on, hold a tissue against the grille, and release.
Because inline fans extract from the room rather than from directly above the cooktop, grease and cooking residue gets drawn through the fan and into the flexible ducting in the ceiling cavity over time. Properties with inline fans need regular professional servicing to clear that build-up. It's also worth noting that inline fans should not be positioned directly above the cooktop. If you're unsure whether the positioning at a property is correct, it's worth having a technician check.
You can't check the filter on a positive pressure system without ceiling access, so leave that to the annual service. What you can check takes about thirty seconds.
Confirm the wall controller is switched on and showing normal operation. A system that's been switched off isn't controlling moisture, even if it was working fine at the last inspection.
Ask the tenant whether the system has been running consistently. The most common reason tenants switch these systems off is that they push air from the ceiling cavity into the house during winter, and that air can feel cold. Most systems have a setting that limits this. The article Why your DVS, SmartVent or HRV system blows cold air in winter covers what to look for and how to adjust it.
Look at the ceiling diffusers in each room. A ring of dark dust around the vent face, sometimes called ghosting, is a sign the system has been pushing air through a filter that needs replacing.
If there's condensation on windows or dampness on walls in a property where the system is switched on and running, it needs a service.
Any of the following at a routine inspection is a reason to book a service before the next tenancy begins.
Heat pump filter missing, collapsed, or heavily clogged. Black spotting visible on the indoor unit housing or fan through the louvres. A smell from the indoor unit or ducted system at start-up. Unusual sounds from any unit, grinding, rattling, or whirring. Fault codes showing on the indoor unit display. Ducted supply vents with no airflow. A ducted system that's running but not heating or cooling as expected. Bathroom extractor failing the tissue test. Kitchen rangehood filter visibly blocked with grease. Positive pressure system switched off, showing a fault, or with visible ghosting at the diffusers.
Most of these issues come down to a lack of maintenance rather than a system fault. A service resolves most of them. Where it doesn't, the technician will be able to identify what's causing the problem and advise on next steps. If you'd like to understand what a professional service covers before you book, the article on what a professional heat pump service includes in Auckland walks through each step.
Annual professional servicing for all systems is the standard regardless of what the inspection finds. The checks above are the early warning layer between services, not a replacement for them.
Three things make a practical maintenance routine for a rental property.
First, a brief written guide for each incoming tenant on how to use the home energy systems in the property. Which mode to run the heat pump in, how often to clean the filter and the rangehood mesh, and who to contact if something seems wrong. It takes a few minutes to prepare and sets clear expectations from the start of the tenancy.
Second, the checks above added to every routine inspection. Document what you find with notes and photos. A consistent record across inspections makes it easy to see what's changed and whether a system is deteriorating between services.
Third, annual professional servicing, or a service at tenancy changeover if the tenancy ran longer than twelve months. A single provider who covers heat pumps, ventilation, and extraction fans is more straightforward than coordinating multiple trades. The service report from each visit is your clearest record of the property's maintenance history.
Yes. Under the Healthy Homes Standards, heating systems need to remain in good working order throughout a tenancy. Tenants are expected to clean accessible filters where it's easy to do so. Professional servicing of the internal components, outdoor unit, and drainage system sits with the landlord. The article on Healthy Homes heating requirements in NZ covers the full breakdown.
Yes. The Healthy Homes Standards require these systems to remain in good working order throughout the tenancy, not just at installation. Annual servicing is the standard. The tissue test at a routine inspection gives you early warning between services. For more on what goes wrong without regular maintenance, the ventilation maintenance guide for NZ rental properties covers each system type in detail.
On a wall-mounted unit, you can check the filter and look at the internal fan through the louvres at a routine inspection without any tools. On a ducted system, the air handler sits in the ceiling space and isn't accessible without ceiling entry. The checks you can do are limited to the return air grille and filter (with a step stool), supply vent condition, airflow to each room, and the outdoor unit. Everything internal requires a professional visit.
Four things you can check without ceiling access: whether the wall controller is switched on and showing normal operation, whether the tenant says it's been running consistently, whether there are dark dust rings around the ceiling diffusers, and whether there's condensation on windows in a property where the system should be controlling moisture. Any of these is a reason to schedule a service.
The tissue test is designed for bathroom extractor fans and kitchen inline fans. For a rangehood, switch it on at low speed and check that you can feel suction from the cooktop surface. Then pull the filter mesh out and check its condition. A visibly greased filter tells you more than the tissue test would.
MiHT Home Energy System Care works with property managers across Auckland to provide scheduled maintenance for heat pumps, ventilation systems, and extraction fans across rental portfolios. If you manage multiple properties and want to discuss what a maintenance programme looks like in practice, the property managers page is a good starting point.