Geyser switch wiring

Geyser switch wiring diagram using a double pole switch
Image from electrical technology.

Geyser switch wiring is the process of connecting a geyser to a geyser switch on the DB board for an electric source. I know someone or you may be asking what is he talking about. First things first what comes to your mind when you hear a person say the word geyser. I think you said it right hot water.

Therefore, a geyser is a device for heating and storing water. Not any other water but hot water. I believe it is important for you to know the function of a geyser switch before you start to wire it.

A geyser switch acts as an isolator. A geyser isolator switch ensures that when it is in the off position, both the live and neutral wires are isolated from the supply. Because of its ability to isolate power, a geyser isolator switch is used to:

  1. Isolate the geyser from the supply for maintenace purposes.
  2. You can use it when you want to replace the geyser element.
  3. Replace the thermostart.
  4. Remove the calcium from both the geyser element and the geyser cylinder when it accumlates.
How To Install A Double Pole Switch
Geyser isolator switch wiring diagram

To start with a geyser switch has 6 terminals on its back. These terminals are three from the supply side and three from the load side. The terminals are labelled L, N and E.

These labels stand for LIVE, NEUTRAL AND Earth. For you to have a clear picture of what I am talking about, check out the video below by Allen Goldsmith.

Video showing how to connect a geyser switch.

geyser wiring connection

How do you connect a geyser to a circuit breaker? from the DB unit to the geyser isolator switch then to the geyser element?

I am glad to tell you that the process of doing this is easy. The first thing that you consider is the size of the circuit breaker. I personally use a 20A circuit breaker for a standard geyser of 100 litres.

If you want, you can use a 15A circuit breaker, it works fine as well. I will guide you on how to calculate the correct size of the geyser circuit breaker in the coming chapters.

This infographic is showing you the process how to connect a geyser from start to finish.
connection of geyser

After you have selected your circuit breaker size, you go ahead and run your cables from the consumer unit to the geyser switch. These are the cables that you connect to the terminals labelled supply on the geyser switch.

Then you run the other cables from the GEYSER element to the switch. These are the cables that you connect to the terminals labelled load on the geyser switch.

Isolator switch for geyser price.

These are low-cost geyser isolator switches, rated at 20A. They are not only affordable, but they are also durable.



Name: Wallpad

Voltage: 110V-250V

Current: 20A

Warranty: 12 years

A place to buy: Buy here now


  • It is very durable,it lasts longer
  • This is made of tampered glass therefore,it does not easily get scratched.
  • It has an elegant look.


Atlectric geyser switch.

Name: Atlectric



Warranty:1 Year

A place to buy: Buy here now


  • It is made of ABS-flame retardant plastic,this protects the switch from fires.
  • It is made of tempered glass to prevent scratches.
  • The switch has overload protection,therefore,it automatically cuts the power when there is an overload situation.
  • This switch is suitable to control geysers,incandescent lamps,energy-saving bulbs, and led lamps.

Tips to consider when Installing a geyser switch.

  1. Make sure the switch you have bought is compatible with the power supply of your country.
  2. Consider the wiring code,if you are not sure please consult a qualified electrician to help you.
  3. Always switch off the circuit breaker that is supplying power to the geyser.
  4. Remove the faulty switch .
  5. Then install the new geyser switch.
  6. Switch on the circuit breaker that you switched off.

How to connect a geyser element and thermostat.

electrical wiring diagram for a single Geyser element.

Connecting a geyser element and a thermostat is a very simple task to do. For you to be successful in connecting a geyser element and a thermostat, you must know that a new geyser comes complete with a thermostat and a geyser element.

Here I must mention that a thermostat is a device that regulates the temperature of the geyser element.

The first thing that you do when connecting a geyser element is to switch off the power supply from either the switch or the circuit breaker.

The second thing is to connect the power cables to the geyser element. A geyser element and a thermostat acts like a plug and a socket. What do I mean? Most if not all of the electrical appliances in your home comes with a plug. You insert the plug into the socket, for you to power your appliance.

When you are connecting the cables to the geyser, you insert the thermostat on top of the geyser element. The terminals for connecting power to the geyser, are located on the thermostat. The terminals are labelled L and N.

You connect the live or hot wire on the terminal labelled L. And you connect the neutral wire on the terminal labelled N.After connecting the power supply to the element, you select the temperature at which you want your water to be heated. You do this using a selector nobe located on the thermostat.

Then you switch on the power and wait to have a warm bath.

Watch the video below by ecological time on how to replace the geyser element and a thermostat.

geyser element.

Geyser switch wiring diagram

I have decided to add these wiring diagrams from electrical technology to help you visualize how the circuits look like. I encourage you to look at the diagrams carefully and understand them.

Electrical diagram for a single geyser element.
Geyser switch wiring diagram using a double pole switch

Geyser circuit breaker size.

I will fail you in my duty if I don’t define what a circuit breaker is. A circuit breaker is an electrical device, that protects electrical machines and equipment. It protects machines and equipment from short circuits and overloads.

How does it protect these machines? When a circuit breaker detects either a short circuit or an overload, it will trip, thereby preventing the machine from being damaged.

Now that you know how a circuit breaker protects equipment, it’s time to know how to choose a geyser circuit breaker size.

Steps to follow when choosing a geyser circuit breaker.

Below is a list of steps that you should follow when selecting a geyser circuit breaker size.

  1. The first step ,you must know the power consumption of the geyser.Every geyser comes with a name plate.On the name plate,you will find the specification for the geyser.
  2. The second step,you should calculate the current required for the geyser to operate.
  3. The third and final step is to choose the correct size of circuit breaker for your geyser.

Now that you know the three steps that you need to choose the correct size of the circuit breaker, let us calculate and then find the circuit breaker size of a 2000W geyser operating on a 230V power supply.

Data to use.

Power consumption in watts(W)= 2000W.

Voltage in volts(V)= 230V.

Current in amperes(A)= ?

From the data above, you can see that the current in amperes is not known. We are going to calculate the current. This is the current required for the geyser to operate.

Power = current x voltage.In our case, we have power and voltage. To find current, you make current the subject of the formula.

P = IV,I =P/V

To find the current, you divide the power consumption of the geyser by the voltage of the power supply.

I =2000/230

I =8.6A.

8.6A is the theoretical current a 2KW geyser will draw. With this current, a geyser will work but not for a long time. That is if you supply this Geyser with an 8.6A circuit breaker.

What do you do to avoid having problems? In this case, you will need a circuit breaker that will give you 125% current more than the calculated current. In our case 8.6A circuit breaker.

When you calculate 125%.You will need a 10.75A circuit breaker size for the geyser. Should you use a 10.75A circuit breaker? The answer is no. Why you ask. The geyser, should not use 80% of the current capacity of the circuit breaker. It can work, but for a short time.

You go for a higher rated circuit breaker than 10.75A here a 20A geyser Isolator circuit breaker will do. Therefore, you should use a circuit breaker size that will cover the geyser needs without using 80% of the geyser circuit breaker amps capacity.

Geyser cable size.

The recommended geyser cable size for a standard geyser is a 4.0mm squared cable. Check the chart for cable sizes below.

This is a chart for cable sizes in a home it includes geyser cable size.
Cable sizes for home installations.

Should you have a question, comment or contribution, feel free to comment in the comments section below.

Geyser switch wiring

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