Questions for hot water system suppliers

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It’s best to sound out an installer to check their reliability before handing over your hard-earned cash. Have they successfully installed this particular hot water system before? What happens if they go out of business? Here are some key questions to get you started.

General questions regarding all systems

  • What’s your experience with heat pumps/solar thermal/PV diversion systems etc?
  • Are you licensed to install this kind of system?
  • What happens if the system needs to be fixed under warranty, and your business is no longer operating?
  • How long have the equipment manufacturers been in the industry, and do they have a local office?
  • What’s the warranty on the tank? And on the other components of the hot water system?
  • Does the quote include all system components as well as installation? Does the quote include all labour, transportation and inspection charges?
  • What maintenance is required on the system?
  • Are replacement parts readily available?
  • How long can I expect my system to last?
  • How long will it take to install the system?
  • Do you handle the rebate application process? How many STCs does my system qualify for?
  • What material is the tank?
  • Will the installation be designed to reduce weathering of the storage tank?
  • What level of insulation and lagging do you offer on the system?
  • Do you install any measures to prevent heat coming out of the pressure relief valve?
  • What is the maximum output water temperature and is a tempering valve included? (Note tempering valves are compulsory)
  • Will the system meet the household’s needs regarding number of occupants and bathrooms?
  • Can I retrofit my current system?
  • If you’re looking at an electric hot water system, ask if they can set up a timer so that it runs in the middle of the night, or in the middle of the day if you’re on solar.

Questions for heat pump installers
It’s important to differentiate between high quality heat pumps and those that are less efficient. The best heat pumps will have a coefficient of performance of 3.5 to 4 or higher, while some of the lesser quality heat pumps may be down at 2 to 2.5. Some tradespeople will also tell you that heat pumps don’t work in cold weather. A more accurate statement is that some brands don’t work in the cold, while others actually work quite well. One way to compare heat pumps is by the number of STCs they receive for your climate zone, available at, with more STCs meaning they operate more efficiently in that climate zone. “They’re too noisy” is also another comment about heat pumps, whereas only some brands are actually noisy – look for a heat pump with a noise rating less than 50dba. Here are some questions to help pick a quality heat pump.

  • What’s the heat pump’s coefficient of performance?
  • What is the heat pump’s coldest operating conditions, or operating temperature range?
  • What is the heat pump’s noise rating?
  • Does the compressor have a block out timer/timing function?
  • Does the heat pump have a resistive element? (If so, it could mean that the actual heat pump doesn’t work as well as others. You’d also need to be wary of what impact the resistive element could have on household electricity use.)
  • What is the tank warranty, compressor warranty and installation/workmanship warranty?
  • What’s the process to enact a tank or compressor warranty after the installation warranty has expired?
  • Are there any additional costs such as safety switch costs, set up for block out timing (to match solar PV generation times), or extra cost for an elevated work platform?

Questions for solar thermal installers
Solar thermal systems can take a number of days to install due to the plumbing and roofwork involved. Quiz your installer about the full installation process.

  • How well does the system perform in overcast conditions?
  • Will my roof need to be strengthened for a close-coupled system?
  • What is the tank, collector, booster and installation warranty?
  • Will my system need a tilt frame?
  • Does the system come with freeze protection?
  • How long will it take to install the complete system?

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