Heating water is one of an average household’s biggest electricity spends. In the UK water heating and central heating systems are usually integrated and managed with a time switch as standard, but here in South Africa our water geysers up till recently have often been left to run all day and night. The conventional wisdom was that it uses more power to heat water from cold than it does to maintain the heat throughout the day. This may be true if the hot water taps aren’t being switched on and off all day, and if you have a very efficient blanket retaining the heat in the geyser, but how many of us do?
We tried manually switching off in the day and on again in the evening, but what with human error and kids ending up with cold showers, plus the fact that for early morning showers it needs to be left on all night, it was only a partial success. So we finally got around to installing a timer on our geyser. The new rail timers are tiny and just clip into the main fuse box. We have the one pictured above from CBI. They are totally digital so you can program in exactly what times you want and easily override the timer when needed (human error might kick and forget to re-activate the timer at this stage of course!).
We’ve yet to see how much we are really saving as our electricity reading is for the whole farm, four houses and the borehole pumps. There hasn’t been a huge difference in our monthly bill yet, but we are still working our way round trying to find out where the biggest electricity drains are. What we need is a rail meter just for our house so that we can experiment and see what measures actually do make a significant difference.
The next step is to rig up a solar water heating system to run in tandem with our regular geyser. Apparently you can save up to 70% of electricity used for water heating if you pre-warm the water that goes into the main geyser, so that it’s not constantly heating up the water intake from cold. This could be through an actual solar geyser, (which will do most of the water heating in summer and then can be topped up by the regular geyser in winter, at night or on dull days) or just through a home-rigged system of black pipes coiled on the roof, warmed by the sun and taking the edge off the ground water chill.
Do you have a timer and if so have you noticed it making a difference to your monthly electricity bill?