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Expert Hot Water System Repairs & Installations in Auckland

Mainly Gas And Plumbing is your certified, local specialist for all hot water systems in Auckland.

Whether you need an urgent repair or want to upgrade to a modern, energy-efficient system, we guarantee reliable hot water when you need it most.

 

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Auckland's Hot Water Experts: Repair, Replace & Upgrade Your Cylinder or Continuous Flow System

Mainly Gas And Plumbing is your certified, local specialist for all hot water systems in Auckland. Whether you need an urgent repair or want to upgrade to a modern, energy-efficient system, we guarantee reliable hot water when you need it most.

 
Fully Installed Specials
Why Choose MGP?

Mainly Gas And Plumbing is your certified, local specialist for all hot water systems in Auckland. Whether you need an urgent repair or want to upgrade to a modern, energy-efficient system, we guarantee reliable hot water when you need it most.

Certified Plumbers & Gas Fitters

Our team of plumbers and gas fitters are PGDB registered and ready to go.

Emergency Hot Water

Can’t wait when waiting to get a repair complete, MGP has emergency temporary hot water crash kart systems ready to install.

Same-Day Service

When it comes to hot water there’s no mucking around, our team is ready to answer the call.​

Guaranteed Workmanship

Quality Installation backed by our MGP guarantee

The Energy Efficient Solution

Types of Hot Water Heat Pump Systems:

There are generally two main configurations for Hot Water Heat Pump (HWHP) systems: Integrated (or All-in-One) and Split Systems.

 

Integrated (All-in-One) Systems

The most common type, where the compressor, fan, evaporator, and water storage tank are combined into a single, compact unit.

• Design: Resembles a traditional electric storage tank, but with a heat pump unit mounted on top.

• Installation: Simpler and typically less expensive to install, as the unit is pre-assembled and only requires standard plumbing and electrical connections. It must be placed in a location where it can draw heat from the air.

• Best For: Homes where the unit can be placed outdoors or in a garage/utility room with adequate air circulation.

• Pros: Lower upfront cost, easier installation.

• Cons: Requires more floor space than a split system. If installed indoors, it can cause the immediate surrounding area to be cooler (a benefit in summer, a drawback in winter).

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Split Systems

In a split system, the main components are separated: the heat pump unit (compressor, fan, evaporator) is located outdoors, and the water storage tank is located indoors or sometimes outdoors, connecting to the heat pump unit via refrigerant lines.

• Design: The outdoor unit looks similar to an air conditioner condenser. The indoor tank is often designed to blend more easily into a home environment.

• Installation: More complex as it requires running refrigerant lines between the two units, typically resulting in a higher installation cost.

• Best For: Homes with limited indoor space, or in colder climates where keeping the main tank indoors helps maintain water temperature.

• Pros: More flexibility in placement, allows the tank to be hidden away, and can sometimes be retrofitted to an existing hot water storage tank.

• Cons: Higher installation cost and complexity.

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Hot Water Heat Pump FAQ

​How loud are they?

Modern hot water heat pumps are generally quiet, similar to a standard air conditioner unit or slightly louder than a refrigerator. Most units operate in the range of 45 to 55 decibels (dBA). Placement (e.g., away from bedroom windows) can help mitigate any noise concerns.

​Can they work in cold weather?

Yes. While their efficiency (COP) is highest in warmer weather, modern HWHPs are designed to operate effectively in low temperatures, often down to -5°C or lower. Many units include an electric booster element that automatically turns on in extremely cold conditions or during periods of very high hot water demand to ensure you never run out of hot water.

How long do they last?

With proper maintenance, the lifespan of a heat pump hot water system is comparable to a conventional storage system. You can typically expect the tank to last 10–15 years and the heat pump mechanism (compressor) to last 8–15 years. Regular maintenance checks can help maximize their longevity.

The Traditional Standard 

Lower Upfront Cost

The most compelling reason is the initial investment.

  • Lowest Capital Outlay: Electric cylinders are significantly cheaper to purchase and simpler to install than heat pump water heaters. A standard electric cylinder installation can often cost $3,000 to $4,000 (including unit and labor), while a hot water heat pump installation often starts around $7,000.

  • Quickest Solution: They require minimal complexity—no outdoor unit, refrigerant lines, or specialized pipework. For an urgent replacement or a simple like-for-like swap, an electric cylinder is the fastest and most affordable option.

  • Budget Constraint: If a household has an immediate need for a new water heater and a limited budget, the electric cylinder provides the lowest barrier to entry

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Simplicity and Reliability

The basic design of an electric cylinder offers unmatched reliability and easy maintenance.

  • Few Moving Parts: It only contains an element, a thermostat, and a safety valve. There is no complex compressor, fan, or heat exchanger. This lack of complexity makes the system highly reliable and less prone to mechanical failure.

  • Minimal Maintenance: Maintenance is typically limited to checking the safety valve and, sometimes, replacing a sacrificial anode rod. This results in lower long-term repair costs compared to a heat pump system.

  • Easier Replacement: Electric cylinders are compatible with almost all existing plumbing and electrical systems, making them the most straightforward choice for retrofitting or replacing an existing unit.

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Indoor and Small-Space Installation

The unit’s contained design makes it suitable for specific environments.

  • Silent Indoor Operation: Since the cylinder is often installed indoors (in a cupboard, laundry, or attic), the heating process is essentially silent. This is a benefit over heat pump units, which have an outdoor fan and compressor that generate noise (typically $45-55 \text{ dBA}$).

  • No Climate Dependency: Unlike a heat pump, which draws heat from the ambient air, the electric cylinder’s performance is completely unaffected by cold winter temperatures. It delivers consistent, reliable heat no matter how cold the garage or outdoor air gets.

The High-Performance Workhorse

A gas hot water cylinder uses a gas burner (located at the bottom of the tank) to heat water. It combines the storage capacity of a traditional cylinder with the raw heating power of natural gas or LPG.

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Why Choose a Gas Hot Water Cylinder?

For many, gas storage is the “gold standard” for reliability and performance. Here are the top reasons to install one:

  • Rapid Recovery Rate: This is the biggest advantage. Gas can heat water significantly faster than a standard electric element. If a large family uses all the hot water in the morning, a gas cylinder can reheat the entire tank in a fraction of the time it takes an electric one, ensuring the next person doesn’t get a cold shower.

  • Reliability During Power Outages: Many gas cylinders use a “standing pilot” or battery-powered ignition system. This means that even if the electricity goes out during a storm, you will still have a tank full of steaming hot water. Unlike heat pumps or most continuous-flow units, they don’t necessarily need the grid to stay hot.

  • Superior Water Pressure: Because these are usually mains pressure systems, they offer incredible flow rates. If you have a high-end rain showerhead or multiple bathrooms being used at once, a gas storage cylinder provides a more consistent, powerful experience than many smaller instantaneous units.

  • Simple Replacement for Electric: If you already have an electric cylinder but find it’s too slow or expensive, switching to gas storage is often a simpler plumbing upgrade than moving to a continuous-flow system, which might require extensive new pipework.

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Natural Gas vs. LPG

Depending on where your customers live, they will use one of two fuel types:

  • Natural Gas (Mains): Delivered via underground pipes. It is usually the most cost-effective way to run a gas cylinder and never runs out.

  • LPG (Liquefied Petroleum Gas): Delivered in large 45kg bottles. LPG has a higher energy content than natural gas (it burns “hotter”), but you have to monitor the bottles so you don’t run out. It’s the perfect solution for rural properties or homes without street gas.

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The “Recovery Rate” Advantage

The biggest technical selling point for a gas cylinder is the Recovery Rate. This is the amount of water the unit can heat back up to 60 degrees Celsius in one hour.

  • Electric: Takes a long time to reheat (often 2–3 hours for a full tank).

  • Gas: High-performance gas cylinders can often reheat the entire tank in under an hour.

  • First Hour Rating: If you have a 180L tank and a high recovery rate, your “First Hour Rating” might be 350L+. This means you can effectively use much more hot water than the tank actually holds because it’s reheating while you shower.

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Endless Hot Water on Demand

Unlike traditional systems that keep a large tank of water hot all day, a gas continuous flow system only heats water when you turn on a tap. It is a compact, high-efficiency solution that ensures you never run out of hot water, no matter how many people have showered before you.

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Key Benefits of Continuous Flow

  • Never Run Out: Because it heats water as it flows, the supply is effectively limitless. It’s perfect for big families or homes with giant soaking tubs.

  • No Standby Heat Loss: Storage tanks lose heat through their walls 24/7 (standby loss). Continuous flow units eliminate this, making them highly energy-efficient.

  • Space-Saving Design: These units are roughly the size of a small suitcase and are usually mounted on an external wall. This frees up valuable cupboard space inside your home.

  • Precise Temperature Control: Most models allow you to install digital controllers in your bathroom or kitchen, letting you set the exact temperature so you don’t have to mix in cold water.

  • Longer Lifespan: Without a large tank to corrode or leak, these units often last up to 20 years—nearly double the life of a standard storage cylinder.

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Condensing vs. Non-Condensing Technology

When choosing a unit, the biggest technical fork in the road is whether to go with a Condensing or Non-Condensing model.

​Condensing units capture the heat from the exhaust gases that would otherwise be wasted. If you have a large family or high gas prices, the extra $200–$400 upfront for a condensing unit usually pays for itself in 2–3 years.

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The Power of Digital Controllers

Digital controllers are often sold as accessories, but they are essential for getting the most out of these systems.

  • Precision Safety: You can set the bathroom controller to exactly 42°C, eliminating the need to “mix” in cold water. This prevents accidental scalding, especially for children or the elderly.

  • Energy Savings: When you don’t have to mix cold water to find the right temperature, the unit doesn’t have to heat the water to a higher-than-necessary temperature, saving gas.

  • Bath Fill Mode: Some controllers allow you to set a volume (e.g., 150 liters). The unit will fill the tub and then automatically turn off and beep when finished.

Heating with the Power of the Sun

A Solar Hot Water System uses solar collectors on your roof to absorb heat from the sun and transfer it directly to your water supply. In many climates, a well-sized solar system can provide 60% to 90% of a household’s hot water for free.

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How it Works

  • Absorption: Solar collectors (panels or tubes) on the roof capture solar radiation.

  • Transfer: In Direct Systems, the household water itself flows through the panels. In Indirect Systems, a specialized heat-transfer fluid (like glycol) flows through the panels to prevent freezing.

  • Exchange: The heat is transferred into a storage tank, usually via a heat exchanger.

  • Booster: On cloudy days or during high-demand periods, an electric or gas booster kicks in to ensure the water reaches the required temperature usually 60 degrees Celsius. 

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Types of Solar Collectors

There are two main technologies used to capture the sun’s heat. Choosing the right one depends on your budget and local climate.

 

Flat Plate Collectors

These are the most common and traditional type. They look like thin, dark solar panels.

  • Best For: Warm to temperate climates with plenty of direct sunlight.

  • Pros: Lower upfront cost, very durable, and high efficiency during peak summer.

  • Cons: Efficiency drops significantly in very cold or cloudy weather as heat escapes from the large surface area.

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Evacuated Tube Collectors

These consist of a series of glass tubes. Each tube has a vacuum inside it, which acts like a “super-insulated thermos.”

  • Best For: Cooler climates, frost-prone areas, or locations with more cloud cover.

  • Pros: Extremely efficient at retaining heat; can work in temperatures as low as -15 degrees Celsius.  They also “track” the sun better throughout the day due to their round shape.

  • Cons: Higher initial cost than flat plates; can be prone to overheating in extremely hot summers.

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Why Install a Solar Hot Water System?

  • Zero Carbon Heating: Once installed, your hot water is generated by a 100% renewable resource with zero emissions.

  • Massive Bill Reductions: By displacing 60-80% of your water heating energy, the system eventually pays for itself through energy savings.

  • Adds Property Value: Eco-friendly homes are increasingly in demand, and a visible solar system is a clear signal of a sustainable, low-cost-of-living home.

  • Long Lifespan: Quality solar collectors are built to last 20 to 25 years, significantly longer than many standard electric tanks.

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Key Considerations for Homeowners

  • Roof Orientation: For maximum efficiency, collectors should ideally face True North (in the Southern Hemisphere) at an angle that matches your latitude.

  • The “Booster” is Essential: Solar is a “pre-heater.” You still need a gas or electric backup to guarantee hot water during a week of rain or in the middle of winter.

  • Maintenance: Every 3–5 years, you should have a professional check the glycol levels (in indirect systems) and the sacrificial anode in the tank to prevent corrosion.

Why the Hot Water Heat Pump is Our Top Choice

While every system has its place, the Hot Water Heat Pump (HWHP) has emerged as the clear winner for most households in 2025. Here is why it should be at the top of your list:

 

1. The “Free Energy” Factor

A heat pump is the only system that can be more than 100% efficient. While an electric heater turns 1 unit of power into 1 unit of heat, a heat pump uses that same unit of power to “move” 3 or 4 units of heat from the air into your water. You are essentially getting 70% of your hot water for free.

2. Future-Proofing Your Home

The world is moving away from fossil fuels. Gas prices are rising, and many new developments are no longer even connecting to gas lines. By installing a heat pump, you are “electrifying” your home, making it compatible with a carbon-zero future and increasing your property’s resale value.

3. The Perfect Partner for Solar PV

If you have (or plan to get) solar panels on your roof, a heat pump is a “game changer.” You can set the heat pump to run during the day when your solar panels are producing peak power. This allows you to store that solar energy in the form of hot water, effectively acting like a thermal battery for your home.

4. Versatility and Safety

Unlike gas systems, there is no combustion, no flues, and no risk of gas leaks.5 Unlike solar thermal, you don’t need to reinforce your roof or worry about heavy panels—the heat pump looks and acts just like a standard tank but works much smarter.

 

The Verdict:

Choose Electric Storage only if your budget is extremely tight and you need a quick fix.

Choose Gas Continuous if you have zero floor space and an endless supply of teenagers.

Choose Solar Thermal if you live in a permanent sun-trap and have a very high initial budget.

Choose a Heat Pump for everything else. It offers the best balance of long-term savings, environmental responsibility, and modern performance.

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