Why Does My Hot Water Keep Going Cold?

24 February 2025

There can be several reasons as to why your hot water keep going cold. It can be extremely frustrating taking a shower when the water temperature fluctuates hot and cold. Here we can explore a few reasons as to why this may be happening.

Overusing Hot Water

By using too much hot water at one time this can be a reason, if you are consuming water faster than it can be heated. By staggering the times someone else has their shower, this can help the hot water running continuously.

Hot Water Tank Is Too Small

Depending on the size of your hot water tank, unvented cylinders or property requirements, your tank may be too small for your property. If this is the case consider a new hot water tank more adequate for your property and central heating system.

Broken Heating Element (Immersion)

A faulty heating element can be the reason why your hot water is not heating. Over time the element can wear out. Having your central heating serviced and well maintained will help this situation.

Blocked Heat Exchanger

Intermittent hot and cold showers can be a strong indication of a faulty heat exchanger on a boiler. It may be blocked with sediment, sludge and magnetite if you have a combi boiler installation, requiring power flushing. Particularly if there is no filter currently present on the central heating.

Sediment Build-Up

This can cause blockages and can accumulate in the boiler installation. If you are hearing loud noises from the boiler this can be a strong indication of signs of sludge or sediment in the system.

Broken Thermostat

If your smart thermostat is not functioning correctly this can be a reason as to why your hot water is not heating correctly.

Poor Maintenance and Old Parts

Neglecting boiler service and maintenance can cause hot water issues. Having your central heating system regularly checked and inspected will prolong the life of your heating system.

Inefficient Pipes

Poorly fitted or leaking pipework can be another issue, effective pipework is essential for transporting hot water. Upgrading and insulating pipework is something that can improve your hot water productivity.

Old Heating System

Your central heating has a lifespan generally of around 6 – 15 years. After this the efficiency may drastically decrease. If your boiler installation is nearing the end of life you may want to consider upgrading to a new energy efficient boiler from a Worcester Bosch Accredited Installer.

Inconsistent Power Supply

Modern central heating systems typically rely on electricity and if you have unstable power this can lead to inefficient hot water. There are alternatives you can look into like solar panels or generators that may help with this issue.

Final Thoughts

It can be very frustrating having your shower run cold. By running through a few of these simple checks you can identify the underlying cause. AWP Boiler Installations can provide you with a range of boilers if your problem persists and you feel like it is time to invest in a new boiler or central heating system.

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