Coolblue home
Written by Julie

How do I prevent my fuses from blowing?

An electric patio heater requires a lot of power. If the requested power is greater than the power group can handle, there is a chance that the fuses will blow. In this article, we'll explain what peak power is and how you can prevent short circuiting.

Peak power

Peak power

To provide you with heat, a heater requires a lot of power. That can sometimes be a problem for your electric circuit. Every device uses more power to start up. We call that peak voltage. When you switch on a device, it often requires 2 to sometimes 10 times more power than when your patio heater works normally. With a heater of 1,000 watts, that means 2,000 to 10,000 watts. That peak voltage only lasts 1 second. Your heater will then run on normal power. But that one second is sometimes enough to cause trouble. When there's more power than your electric circuit can handle, the fuses will blow. And that is annoying.

Electric circuits

Electric circuits

A standard house installation has groups of 16 amperes. The total capacity of such an electric circuit is 3,600 watts. When your heater requires more power, the fuse blows. Do you have a heater of 1,000 watts and do you connect it to an empty circuit? Then nothing is wrong. But do you want to heat your garden with 2 heaters of 1,600 watts each and maybe you also have outdoor lamps connected to your electric circuit? Then it becomes a different story. The required power then becomes too high for one second.

Is that bad?

It's not bad, but annoying. If you're unlucky, it may be that after 1 time you have blown a fuse you already have damage to your patio heater. Does it happen more than once? Then your heater is guaranteed to break. And that doesn't make you happy. You can of course solve this by replacing your fuse with a new one, but it's even better to prevent this. And you can.

How do I prevent this?

I'll give you a number of tips to prevent the fuses from blowing.

1. Calculate the total power

Patio heater

Before you connect your heater, always calculate how much power your devices require in total. That can't not be more than 3,600 watts. When calculating, also take the peak voltage into account when switching on your devices. With normal consumption, your devices can, for example, reach up to 3,600 watts, but when switched on the power becomes way too much for a second.

2. Start the heater at the lowest power

Heater with multiple settings

Do you have a patio heater with multiple settings? First turn the heater on at the lowest setting. That way, the peak voltage is less high in the beginning than when you immediately switch on the patio heater at full power. After this you can slowly adjust the heat intensity yourself.

3. Wait a bit before turning on a 2nd patio heater

2 patio heaters

For 2 or more patio heaters that are connected to the same electric circuit, we recommend not switching them on at the same time. First switch on one patio heater and then the other. This way you avoid double peak voltage on your fuse box.

C automatic or a soft starter

Soft starter

Do these tips not work? Then you have 2 options to prevent the fuses from blowing. For the 1st way you need the help of a mechanic. You can have your fuse in the fuse box replaced by a C automatic. These machines are prepared for peak voltages. The second way and the easiest way is to use a soft starter to switch on or dim your patio heater. A soft starter flattens your peak current in such a way that it doesn't hit your electric circuit. In addition, a soft starter extends the life of your heater by up to 30 percent.


Before you connect your patio heater, always calculate the total power of all devices that you connect to your electric circuit. Keep in mind that your devices consume much more power for a second when switched on: the peak voltage.

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