How long does hot water remain heated in a tank?

Your hot water tank serves as the reservoir for your heated water until it’s required. Hence, it’s crucial that your tank is of high quality and crafted from effective insulating materials. A subpar tank might fail to retain hot water for extended periods. This article delves into the duration for which your tank should maintain hot water. Additionally, it provides insights into tank composition, insulation materials, and methods for switching off your tank.

What is the duration for which a water tank will retain its heat?

Several factors influence how long your tank can maintain hot water. Most hot water cylinder manufacturers suggest a heat loss between 1 kWh and 2.5 kWh per day. It’s challenging to pinpoint the exact temperature loss or duration of hot water retention. The kWh unit represents kilowatt-hours, indicating the energy required for heating water. Enhanced insulation enhances efficiency by minimizing heat loss, thus reducing energy consumption for water maintenance at a preset temperature, obviating the need for reheating.

Historically, hot water tanks lacked insulation, but regulations now mandate insulation inclusion upon purchase. Typically, hot water in your tank remains hot for about a day or two, with larger tanks experiencing greater heat loss. The duration also hinges on tank quality and insulation type.

If your tank is closeted, the cupboard’s warmth can gauge heat loss; excessively high temperatures, over 30°C, suggest significant heat loss. To mitigate this, consider an insulating jacket for your tank and insulating pipes with blankets. Adding an extra blanket to the tank improves insulation, ensuring prolonged hot water retention.

What materials are hot water tanks typically constructed from?

Most hot water tanks are made of either carbon steel, stainless steel or copper. Copper is a very expensive metal, which has led to stainless steel being used as a cheaper alternative. In the interest of efficiency, a debate was started about how efficient stainless steel actually is and whether all tanks should instead be made of copper.

There are, however, plenty of benefits associated with stainless steel tanks. One of the main advantages is the reduced risk of corrosion. Stainless steel is slightly more hard-wearing than copper and may keep the water tank free from debris for longer. It is also stronger, particularly in comparison to copper, and therefore the tank does not need to be as thick. Finally, stainless steel is able to withstand high pressures, more so than copper. This is particularly beneficial in the case of unvented hot water cylinders. An unvented cylinder is connected directly to the mains, so a cold water tank isn’t required. This system works under more pressure than a vented system, making stainless steel a suitable material.

Copper has its benefits too. It’s naturally antiseptic in small quantities (large quantities can be poisonous) so, although you won’t be drinking your hot water, the water is purified. Copper is recyclable too, so when you’re replacing your old copper tank, you could get some money back for weighing it in. It’ll be melted down and turned into something else. 

Steps for draining a hot water cylinder tank

Here are the steps to drain a hot water cylinder tank in the UK:

  1. Switch off the power supply to the hot water cylinder. This can typically be done at the fuse box by locating the appropriate circuit breaker or isolator switch for the immersion heater.
  2. Turn off the water supply to the cylinder. Locate the isolation valve on the cold water inlet pipe and close it to stop the flow of water into the cylinder.
  3. Open hot water taps around the house to release any pressure in the system and allow air to enter.
  4. Attach a hose to the drain valve at the bottom of the cylinder. Ensure the other end of the hose is positioned at a suitable drainage point, such as an outside drain or a bucket.
  5. Open the drain valve slowly to allow the water to start draining out through the hose. Be cautious as the water may be hot.
  6. Once the cylinder is completely drained, close the drain valve securely.
  7. If needed, refill the cylinder by opening the isolation valve on the cold water inlet pipe. You may also need to open a hot water tap to allow air to escape from the system as it refills.
  8. Once the cylinder is refilled, switch the power supply back on to the immersion heater.

Remember to follow safety precautions and consult a professional if you are unsure about any steps involved in draining your hot water cylinder tank.

How to switch off a hot water tank

If you suspect an issue with your hot water tank, it’s advisable to completely switch it off until a qualified heating engineer can inspect it.

There are several methods to turn off your hot water tank. You can deactivate it by shutting off the gas, electricity, or water supply. For gas, rotate the dial on top of the thermostat to the Off position. To disable electricity, flip the circuit breaker to the Off position. For the water supply, turn the handle on the water valve clockwise until the flow of water ceases.

Need Assistance?

You can reach out to Ability by completing the form available on our website, calling us at (+44) 01892 514495, or sending a message to Rest assured, we prioritise prompt responses and will get back to you as swiftly as possible. Our goal is to provide you with the necessary help and guidance without delay.

Recommended Posts