Pulsacoil - is it warming up? How to check
There are three ways for the Gledhill Pulsacoil user to know if their Pulsacoil is warming up, or already hot. The first is to simply wait a hour or so then feel the pipes, but generally we need to know immediately.
The second way is by listening. The Pulsacoil has two immersion heater elements and when one (or both) are heating, they usually make a quiet hissing noise rather like an electric kettle makes.
If you can hear this hissing noise you can be reasonably sure the unit has started heating up. Once a cold Pulsacoil has been heating up for an hour or so, it should start producing hot water at the taps.
Listening for the hissing noise is not always a good guide though because not all heaters make a noise when heating. A new appliance or a new heater element for example will often heat the water completely silently. So the third way is to use the electricity meter.
A Pulsacoil technician would probably use a ‘clamp meter” to measure the current in a wire connected to the heater but this is not usually practical for the owner as they are unlikely to have a clamp meter. But there is an almost equally reliable method which needs no tools at all. Look at the electricity meter.
Almost all electricity meters have a red LED on them which flashes when power is being drawn, so this can be used to find out if the heater in the Pulsacoil is drawing power.
The speed of flashing of the red LED varies according to the power being drawn. The faster the flashing, the more power is being drawn.
Conveniently, the LED flashes once per second when three kiloWatts of power are being drawn, and 3kW happens to be the power rating of each of the heater elements in your Pulsacoil. So when your Pulsacoil is heating up, the red LED on your electricity meter should be flashing once per second.
So find your electricity meter, set your Pulsacoil to be heating up, then look at the meter. If the meter LED is flashing once a second you can be fairly certain your Pulsacoil IS heating up, even if it is silent. To finally prove it, turn the Pulsacoil off and check the meter again. The red flashing should slow down to near nothing, then speed up again when you turn the Pulsacoil back ON again.
Below is a short video of my own electricity meter, showing the red flashing LED flashing once per second while a 3kW heater is running. (Filmed in low light so the red flashing shows up.)
Bear in mind that if there are any other high power electrical appliances running in the house or flat at the same time (the cooker for example, or any room heaters) the red LED will already be flashing quite fast. This could be confusing so make sure there are no other heating-producing appliances running.
I’ve written lots more about Gledhill Pulsacoils on my Pulsacoil Repairs website, here:
pulsacoil-repairs.co.uk
Hi Mike,
My wife and I live In a retirement apartment that we bought 6 years ago.
Your common sense description of our Pulsacoil BP storage unit (and how it works) is brilliant and ought to be available to all who have the unit in book form – at a suitable price !
Thankyou for being so ready to simplify what others try to make so complicated.!
Ted Beaumont (96) – CHESTER