Why Is My Instant Water Heater Not Hot?

There is nothing as refreshing as a hot shower. Still, it can be very disappointing when your instant water heater breaks down and produces lukewarm warm water. Not only will you not be able to take a nice hot shower, but even cooking and cleaning will become difficult.

Suppose your water heater does not offer hot water anymore. In that case, it will be best to engage a water heater professional to solve the problem. However, before that, it will be helpful if you understand why your water heater is not hot in the first place.

Below are reasons why your instant water heater is not hot.


Tripped Breaker


The chances are that a breaker trip may have led to your water heater losing its power source which is a water heater problem. If this has happened, then the water present in your tank will start cooling down, transforming it from hot to cold.

Check the electrical panel and flip your breaker to switch it turned on. Wait for a while until your water heater can heat the water again properly. However, if the reset process still results in the breaker trips after a few times, it may be a malfunction of your electrical system or your water heater, which will require professional repair or may call for a water heater replacement.


Incorrectly Set Thermostat

In order to optimize your water heater as well as save money, many people lower the thermostat on instant water heaters. Now, when you need to use the water heater again, you must remember to adjust the thermostat again.

To do this, check the thermostat on the instant water heater and set it to the right temperature. However, remember not to go beyond 120°C as that may make the water too hot.


Broken Thermostat


For instance, even after turning the thermostat up on your water heater and the water still does not reach the desired temperature, then perhaps, it is a sign that your water heater is faulty – due to a broken thermostat.

In that case, you cannot repair things on your own and rather need the help of a water heater professional like Water Heater City Singapore. The water heater professional will inspect your instant water heater to find out if there are any issues. If there are any water heater issues, they may advise you to either repair or replace your water heaters.


Defective Parts

The elements found in the electric water heater, or also known as the immersion heater, are important components of instant water heater tanks. If one of them has become faulty, then your water heater will not work as effectively.

Your second water heater can only help to heat your water as much as it becomes lukewarm. In this situation, you will again need to contact a water heater professional to fix your water heater.


Leaking Tank

Though this may not be visible to you, there may be a water heater leakage in your tank. If you are unsure about the reason for this water heater leak, then do engage a water heater professional right away.

The water heater professional will service the leaking water heater – which can otherwise lead to more severe leaks in the future. Also, other water heater issues may cause trouble in the future. In that case, the professional will quickly identify and fix them as well.


Worn Out Water Heater


An instant water heater normally can last for around ten years as its maximum lifespan. The older they get, the more they start wearing out, and thus, they do not heat your water as effectively.

In case your instant water heater is producing lukewarm water, considering the time of usage, then repairing or replacing your water heater with a new one may be your only option.



We all want a warm shower bath after a long day, and that can be achieved when you have a water heater installed. After installing a water heater, it is best to also schedule regular water heater maintenance in order to maintain the water heater performance. Factors such as a tripped breaker, incorrect thermostat setting, a leaking tank, or overuse of your instant water heater can lead to it not heating. When all of these are present in your water heater, it is advisable to have it repaired or replaced by a professional water heater service provider like Water Heater City Singapore.


Water Heater City Singapore offers complete water heater services for both storage and instant water heater tanks including water heater installation and replacement, and water heater leak. We can provide the supply and installation or replacement of Singapore’s most popular water heater brands like Ariston water heater, Rheem water heater, Joven water heater, 707 water heater, Rubine water heater, and Champs water heater. If required, we are also able to open false ceiling, patch it back up and paint it to restore it to its original condition. We have over 10 years of experience for installation of water heaters and have done hundreds of water heater installation cases for landed, condo and HDB, including complete one-stop installation above false ceiling, plastering, and resealing false ceiling. We are a highly recommended Water Heater Services Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook.  WhatsApp us at +65 8241 0032 for transparent quotations and honest pricing for all your water heater needs. We also provide a fast and efficient service to solve any of your water heater needs!

Related posts