Hot Water Cylinder Troubleshooting: Common Issues and How to Fix Them
A reliable hot water supply is essential for every home. But when your hot water cylinder is not working, it can quickly throw your home’s daily routine.
There are a series of common issues that arise with hot water cylinders - whether you're dealing with a leaking hot water cylinder, no hot water, or just trying to figure out how to test your hot water cylinder, we’ve got you covered.
Common Hot Water Cylinder Issues
1. No Hot Water From the Cylinder
If your cylinder isn’t heating water, here are the usual suspects:
Electrical issues
Power supply issues: Check your circuit breaker to ensure the hot water cylinder is receiving power.
Faulty thermostat or element: The hot water cylinder element or thermostat may need replacing (or maybe both). These are found under a cover located at the bottom of the cylinder.
Plumbing issues
Faulty tempering valve: This valve is found on the outlet side of the hot water cylinder and is there to reduce the hot water temperature to 50 degrees celsius. There should be 1m of copper between the outlet of the cylinder and the valve. If the copper pipe off the top of the cylinder is still nearly too hot to touch but you still have cold/lukewarm water then this valve needs adjustment or replacement.
Leaking hot water cylinder: The hot water cylinder has failed and is now leaking. This can lead onto causing electrical faults as water and electricity don't mix.
🛠 What You Can Do:
Test the cylinder’s power supply, reset the breaker if needed (in your power box), and check the thermostat settings. If that doesn’t solve the issue, it’s time for professional help - this might be a plumber or it may be an electrician. Don’t hesitate to call your usual plumber who will be able to recommend an electrician for you if it’s not a plumbing issue.
2. Hot Water Cylinder Leaking
Leaks can range from minor drips to major water loss, indicating potential issues with valves, seals, or the tank itself. Because of this, the potential flooding can also range from minor to major!
🛠 What You Can Do:
Turn off the water supply to your cylinder immediately. You can do this by locating the isolation valve near the cylinder. If you’re unsure how to turn off your hot water cylinder, give your plumber a call for guidance.
3. Water Not Heating Fully
If your water isn’t getting as hot as it should:
The thermostat may need adjustment or replacement.
Tempering valve needs adjusting or replacement.
🛠 What You Can Do:
This one’s for the experts - Call your electrician or plumber to sort.
4. Unusual Noises from the Cylinder
When the element turns on you can hear the cylinder heat up (sounds like a kettle boiling). This is a lot clearer on older cylinders (pre-2000) but can still be heard on modern ones if it is quiet enough. On newer cylinders (post-2000) you can put your ear to the metal casing and hear a low frequency noise. Try turning it on and off to distinguish the difference.
🛠 What You Can Do:
Nothing needs fixing unless it’s as loud as a kettle then call an electrician or plumber.
How to Test Your Hot Water Cylinder
Testing your cylinder helps pinpoint problems early. Here’s how:
Check the thermostat: Ensure it’s set to an appropriate temperature (typically between 60-65°C).
Inspect the element: Use a multimeter to test if the element has continuity.
If you’re not confident doing this, our team is just a call away for a safe and thorough inspection.
When to Call Ka Pai Plumbing
Some issues, like replacing a thermostat or addressing a leak, need professional expertise. Attempting DIY fixes on major problems could worsen the situation or void warranties.
Our experienced team specialises in hot water cylinder repairs and maintenance. We can quickly identify the root cause of the issue and provide lasting solutions. Fill out our contact form and we will be in touch.
FAQs
Q: How do I turn off my hot water cylinder in an emergency?
A: Locate the isolation valve at the inlet/bottom of your cylinder and turn it clockwise if you have an old school valve or quarter turn if you have a tee handle to shut off the water supply. You may also need to turn off the power.
Q: How can I prevent future problems with my hot water cylinder?
A: Regular maintenance, including opening the TPR valve at the top of the cylinder and checking the thermostat, goes a long way. Doing a visual check of all plumbing connections. Our team offers maintenance services to keep your cylinder in top shape.
Q: What’s the lifespan of a typical hot water cylinder?
A: With proper care, most cylinders last between 10–20 years but only have a life expectancy of 10 years. Regular inspections can help identify issues before they become major repairs.
Get in touch!
Have a hot water cylinder issue, or think your hot water cylinder needs replacing? Fill out our online form for a free quote.