What you are seeing is the result of a type of power load management, know as ripple control. Load management is used to allow utilities to reduce electricity demand during peak usage times. This is a cheaper and more reliable alternative to using peaking power plants, of which some can take more than an hour to bring online, which makes load management even more critical if a plant goes offline unexpectedly.
Ripple control is the most common form of load management, and is used in many countries worldwide. It works by superimposing a high frequency signal, usually between 100 and 1600Hz onto the standard 50-60 Hz main power signal. When devices which are attached to the non-essential loads receive this signal, they shut off the load until the signal is disabled. Affects devices can include residential electric hot-water heaters, air conditioners, pool pumps and crop-irrigation pumps. This includes your hot water cylinder.
When connected to a power network that runs load control, devices are outfitted with communicating controllers that run a program that limits the duty cycle of the device. Consumers are usually rewarded for adhering in the load control program by paying a reduced rate for energy in off-peak times. Controllers are available for ripple control which will ensure your devices run during off-peak times and you will save money by paying a lower tariff.
To find out more about ripple control for your water heater, talk to us today. If you are not on ripple control and you don’t have hot water, check out our “No Hot Water Troubleshooting Page” to diagnose the problem.