Why Is My Electric Shower Going Hot Then Cold And How To Fix It

Electric showers encounter plenty of faults over the course of usage and it is important that you have basic DIY skills otherwise you will have to be seeking the services of an electrician or plumb on a regular basis. Well, sometimes you’re going to need to call a service guy whether you are DIY-skilled or not. This depends on the extent of the issue your electric shower is having.

In this article, we are focusing on why the electric shower goes hot and then cold when in use. We are also going to share with you how this issue can be resolved in case you encounter it in your home.

Water Pressure at the shower inlet

This is one of the most common things that would cause your electric shower to go hot and then cold. The normal pressure needed for a normally functioning electric shower is about 1.5 bar static and 1.0 bar running pressure. However, just before you conclude that this is the cause of the changing temperature of the water in your shower, try to observe and see if you will notice some clicking sound inside the unit. If you hear any clicking sound, there are high chances that they are a result of the low pressure switch that is triggered whenever the pressure of the water at the shower inlet drops. The pressure at the inlet could drop because of a clogged mesh or a malfunctioning valve both of which can be fixed pretty easily. You can either replace the mesh and/or the valve or clean it up to get rid of the clogging debris/particles.

Limescale accumulation

Another cause of this occurrence is the accumulation of limescale inside the hot water canister. If you are living in a hard water area, there are very high chances that your hot shower will be affected by limescale. If you do not clean your hot shower on a regular basis, you are going to face this problem. This is why it is always advisable to descale the water canister on a regular basis. Descaling helps to get rid of the limescale that could potentially affect the pressure of the water in the hot shower. If descaling fails to work, then you might need to replace the entire unit. If you want to prolong the descaling intervals, then it is recommended that you install a magnetic softener in the inlet pipe. This will go a long way in preventing the accumulation of scale in the hot shower.

Electrical Fault

This is another possible cause of the problem and it occurs when the heat can is ground to earth in a similar way the oven’s heating element does. If this happens because of your hot shower going hot then cold, the only way to fix it is by replacing the heat can. This is one of the problems that would require an electrician to troubleshoot because it is somehow difficult to establish it by yourself with basic DIY skills. It is worth noting that this is not the only electric fault that could cause an electric shower to provide hot and the then cold water. Most of the other causes can only be identified through a thorough examination.


In summation, the main causes of your electric shower going hot and then cold is a drop in the pressure of water in the in the inlet pipe, an accumulation of limescale in the water canister and an electric fault. The problem of dropping pressure and that of limescale accumulation can be easily resolved using basic DIY procedures but that of an electric fault would require the service of an electrician.

About the Author Harry Thompson

Gaining a BSc Honours in building/ property maintenance at the University of Portsmouth Harry went into the field of renovating properties. Along the journey, he has developed a wide variety of home & garden DIY skills such as installing new kitchens and landscaping gardens.