Heating Times for Hot Water Systems: What to Expect

When it comes to daily comfort, few things are more essential than having reliable access to hot water. Whether you’re hopping into the shower, washing dishes, or doing laundry, the time it takes for your hot water system to heat up can make a real difference. Understanding heating times helps you choose the right system for your household and identify when performance issues may require attention.

Heating Times for Different Hot Water Systems

Different types of hot water systems heat water at varying speeds. Here’s what you can typically expect:

• Electric Storage Systems:
  These systems heat water in a storage tank using electric elements. For a full tank of hot water, heating time usually ranges from 60 to 90 minutes, depending on the size of the tank and the wattage of the element.
  
• Gas Storage Systems:
  Gas systems generally heat water faster than electric models. A standard gas storage system can take around 30 to 60 minutes to fully heat a tank, making it a popular option for medium to large households.
  
• Solar Hot Water Systems:
  Solar systems depend on sunlight and may require several hours to heat water, particularly during cloudy or colder days. Most have a gas or electric booster that kicks in when solar energy isn’t sufficient, providing hot water in around 1–2 hours when boosted.
  
• Continuous Flow (Instantaneous) Systems:
  These systems don’t store hot water; instead, they heat water on demand. Heating is almost instantaneous, taking just seconds to a minute for hot water to reach the tap, depending on pipe length and water flow rate.
  

Factors That Affect Heating Times

Even within the same system type, heating times can vary based on a few key factors:

• Tank Size:
  Larger tanks take longer to heat. A 250-litre electric system will naturally take more time to reach temperature than a compact 125-litre unit.
  
• Incoming Water Temperature:
  In colder climates or during winter, water entering the system is colder and requires more time and energy to heat.
  
• System Age and Condition:
  Older systems may heat more slowly due to worn components, sediment build-up, or reduced efficiency of heating elements.
  
• Household Water Usage:
  High demand periods (e.g. multiple showers in the morning) can deplete hot water quickly, causing longer waits for reheating.
  
• Water Pressure and Flow Rate:
  Systems may take longer to deliver hot water if the flow rate is too high or pressure is inconsistent, especially in continuous flow models.
  

Ways to Speed Up Hot Water Heating

Looking to reduce the time it takes to get hot water? Here are some practical ways to improve heating efficiency:

• Insulate Hot Water Pipes:
  Adding pipe insulation helps retain heat, reducing the delay before hot water reaches the tap and improving overall efficiency.
  
• Install a Tempering Valve or Booster:
  Solar systems benefit from boosters (electric or gas), which help deliver quicker heating when solar energy isn’t enough.
  
• Upgrade to a More Efficient System:
  If your current unit is over 10 years old, it may be time to upgrade to a newer, faster, and more energy-efficient model.
  
• Service Your System Regularly:
  Annual maintenance clears sediment build-up, checks heating elements, and ensures all components are functioning properly.
  
• Use a Timer (for Electric Systems):
  Smart timers allow you to preheat water during off-peak hours or just before your regular hot water usage times.
  

When to Troubleshoot Slow Heating Issues

If your hot water system is taking significantly longer than usual to heat up, it may be time to investigate:

• Sediment Build-Up:
  Over time, minerals from hard water can settle in the tank, insulating the heating element and slowing down heat transfer.
  
• Faulty Thermostat or Heating Element:
  Malfunctioning parts can prevent the system from heating water efficiently or maintaining the set temperature.
  
• Leaking Tank:
  A slow leak could mean your system is continuously trying to heat cold water, reducing efficiency and wasting energy.
  
• Blocked or Corroded Pipes:
  If hot water is taking a long time to reach certain taps, there may be pipe blockages or corrosion within your plumbing system.
  
• Outdated System:
  Systems nearing the end of their lifespan often struggle to perform. Replacing an old unit can save time, energy, and money in the long run.
  

Optimising Hot Water Performance at Home

Understanding how long your hot water system should take to heat up—and what affects that timing—can help you plan better and catch performance issues early. Whether you’re working with an electric, gas, solar, or continuous flow unit, regular servicing and smart upgrades can make a big difference in speed and efficiency. If your system isn’t meeting your needs, it may be time to consider a new one.

Builders Discount Warehouse stocks a wide range of hot water systems to suit every home and budget. Visit our store or browse online to find the right solution for fast, reliable hot water.