Questions to Ask Your Heat Pump Installer Before Getting a Quote

Choosing the right heat pump for your home is a big decision—both in comfort and cost. While most people focus on price and brand, there are several other key questions that can save you frustration (and money) in the long run. Before accepting any quote, take a moment to ask your installer the following questions. You’ll quickly see the difference between an experienced professional and someone who just wants to make a sale.

1. What warranty is offered on the hardware—and does it include the installation?

Every heat pump comes with a manufacturer’s warranty, but not all warranties are created equal. Most reputable brands like Fujitsu and Mitsubishi Electric offer five years parts and labour when installed by an accredited dealer. However, that only covers manufacturing defects in the hardware itself.

You also need to ask about the installation warranty—that is, who takes responsibility if there’s a leak, wiring fault, or mounting issue. A professional installer should back their workmanship for the same timeframe as the manufacturer warranty. This ensures that if your system isn’t performing as expected, the installer will return to fix it without extra cost.

2. For replacement units, how does the warranty apply when reusing existing pipework?

Replacing an old heat pump with a new model might seem straightforward—but it’s not always that simple. Different refrigerant gases (for example R32 and R410a) cannot be mixed, and even trace contamination from old pipework can damage a new system.

If your installer plans to reuse the old copper lines, ask:

1. Will the existing pipes be pressure-tested and flushed?
2. Will reusing them affect the manufacturer’s warranty?

The safest option could be to replace the pipework entirely, especially if it’s over 10 years old or uses a different type of refrigerant. Some manufacturers may decline warranty claims if the refrigerant circuit is contaminated or non-compliant—so it’s worth confirming before installation begins. Note that Mitsubishi Electric is the only manufacturer we know of that will warranty units if you are buying an R32 gas unit and your old unit is an R410a unit.

A professional installer should clearly explain your options and help you decide whether reusing or replacing is the right call for your situation.

3. What placement will work best for airflow and efficiency?

Where your indoor and outdoor units are positioned can have a huge impact on performance, energy efficiency, and noise. Don’t just assume “where the old one was” is the best place.

Ask your installer:

1. Will the indoor unit blow air evenly across the room?
2. Is there enough clearance above doors or furniture for air to circulate?
3. Is the outdoor unit protected from direct sunlight, strong winds, or roof runoff?
4. What doors are opened / closed and when?

A good installer will inspect your home and recommend the most efficient airflow path for the indoor unit—usually across the longest length of the room, without obstruction. For the outdoor unit, they’ll consider noise, access for servicing, and airflow clearance around the fan. A few extra minutes of planning can make the difference between a quiet, efficient system and one that struggles on hot or humid days.

4. How do I calculate the right heat pump size for my room?

Sizing a heat pump is both an art and a science. A unit that’s too small will struggle to heat or cool effectively, while an oversized one will short-cycle and wear out faster.

A quick rule of thumb is 1kw of heating or cooling per 10 square metres of floor area for an average insulated home. However, that’s only a starting point. Other factors include:

1. Ceiling height (a high ceiling increases the room’s air volume)
2. Insulation levels (ceiling, walls, and floor)
3. Sun exposure and window area
4. Whether the room is open-plan or closed off
5. Upstairs or downstairs room

5. What are the upsides and downsides of multi-split (multi-outdoor) systems?

Multi-split systems—where one outdoor unit connects to several indoor units—can be appealing for homes with multiple rooms. They reduce the number of outdoor units cluttering your walls and can be more visually discreet.

Advantages:

1. Only one outdoor unit, ideal for tight spaces or aesthetic reasons
2. Reduced outdoor noise and less external piping

Downsides:

1. Can not heat and cool and the same time - it can only do one at a time 
2. More complex installation and possibly a higher initial cost
3. If the outdoor unit fails, all connected rooms lose heating and cooling

For many New Zealand homes, especially single-storey houses, individual split systems (one indoor per outdoor) are simpler and often more reliable long-term. Multi-splits suit smaller homes, apartments, or situations where outdoor space is limited.

Final Thoughts

A quality heat pump installation is about much more than the brand on the box. The questions above help ensure you’re comparing like for like when looking at quotes—and that your investment performs efficiently for years to come.

At Gibson Electric, we take the time to assess your home properly, explain your options clearly, and provide comprehensive warranties. Whether you’re replacing an old unit or installing your first heat pump, our Northland team (offices in Whangarei & Kerikeri) can help you get it right the first time.

Contact us today for a free in-home assessment and quote.

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Kerikeri 09 407 6468 
Whangarei 09 988 9340