Geyser switch-off could backfire

[bekdik]

There seems to much confusion about a geyser being on. Most of the time that a geyser is on, it's off.

I'm thinking that people equate an on geyser with an on light, i.e. an on geyser is consuming electricity, the same as an on light.

The difference is that a geyser has a second on/off switch in its circuit, something called a thermostat. the thermostat is simply an on/off switch which is activated by the water temperature of the geyser. When it cools below a certain temperature, it switches the geyser on and proceeds to heat the water until it reaches a high temperature at which point it switches the geyser off.

If you were to monitor the current flow, you would see that the geyser is pretty much only switched on when hot water is used, which is to be expected.

One simple way to save money is to only use the hot tap when you need hot water. If you don't need hot water use the cold tap.

 

[MyWorld]

Well, we have now proven that switching the geyser off did bring about a saving, BUT our geyser is very well insulated with extra geyser blanket and all the pipes are insulated as well. We get around a 15 degree drop in temperature when switched off in summer. We only switch it on for one hour a night and one hour in the mornings and we have sufficient hot water to last the day.

I could not believe it myself, but it seems insulation is they key here.

 

[The_Unbeliever]

If this is true, then the hot water pipe connections going to any hot water tap should be giving issues with the heating-cooling cycle. And also the piping for hot water. It will expand and shrink.

Or am I wrong?

 

[flamtech]

According to the general manager in Quickhot’s service department, Wietz van Lelyveld, the pipes inside the geyser expand when they are filled with hot water, which is usual. But after five hours or longer without electricity, cold water enters the pipe and the metal contracts. This can lead to welding damage over time and leave your roof dripping from a burst geyser.

This makes sense to me. My geyser is on for only one and a half hour a day, thought I am doing the "right thing", but now I am not so sure anymore.

I must believe Van Lelyveld, because he has nothing to gain if I conserve electricity, in fact he stands to gain if more geysers goes kaput.

 

[flamtech]

If this is true, then the hot water pipe connections going to any hot water tap should be giving issues with the heating-cooling cycle. And also the piping for hot water. It will expand and shrink.

Or am I wrong?

Good point.

 

[Azbubu]

I stay alone and switch my geyser on for about 2 hours in the morning so I can shower in the morning and then again for 2 hours in the evening to shower in the evening. Guess I'm doing more harm that way?

 

[Other Pineapple Smurf]

That's maybe why the best advice is to set the geyser colder than 65, to around 55, where it loses heat slower....

A few months ago I would have argued with you, now after setting mine to 59-60 from 66-67 I can say it works. We have noticed no change in water temp yet I've seen a massive saving in electricity this last month - saved over 100 units last month

 

[noxibox]

If this is true, then the hot water pipe connections going to any hot water tap should be giving issues with the heating-cooling cycle. And also the piping for hot water. It will expand and shrink.

Or am I wrong?

Without clarification the statement makes no sense. I find a geyser does not cool that much when left off for hours, and surely cold water gets into the pipes anyway. I'd expect heating and cooling to be going on regardless.

Well, we have now proven that switching the geyser off did bring about a saving, BUT our geyser is very well insulated with extra geyser blanket and all the pipes are insulated as well. We get around a 15 degree drop in temperature when switched off in summer. We only switch it on for one hour a night and one hour in the mornings and we have sufficient hot water to last the day. Unless Kwikhot have been cutting corners and are hoping to try to blame poor workmanship on turning the geyser off for hours.

I could not believe it myself, but it seems insulation is they key here.

But if your geyser is well insulated then it wouldn't be on much anyway, except when you use hot water.

 

[BigAl-sa]

In the light of this, I wonder what is kwikot's arguments as to how their solar geysers manage to survive. Mine is on the roof (outside), on during the day (it is solar), and off at night. Currently, I reckon temps on the roof are below 0°C at night, and the geyser feels that, regardless of how good the insulation is - hot water is non-existent in the morning.

 

[noxibox]

In the light of this, I wonder what is kwikot's arguments as to how their solar geysers manage to survive. Mine is on the roof (outside), on during the day (it is solar), and off at night. Currently, I reckon temps on the roof are below 0°C at night, and the geyser feels that, regardless of how good the insulation is - hot water is non-existent in the morning.

And their in roof geysers are used in several solar heating systems which all include timers.

 

[Sherbang]

http://www.iol.co.za/news/south-africa/gauteng/geyser-switch-off-could-backfire-1.1091855

Quickhot, one of the top suppliers of geysers nationwide, told The Star that turning off your geyser during peak times isn’t a bad idea, but leaving it off overnight can lead to permanent welding damage.

According to the general manager in Quickhot’s service department, Wietz van Lelyveld, the pipes inside the geyser expand when they are filled with hot water, which is usual. But after five hours or longer without electricity, cold water enters the pipe and the metal contracts. This can lead to welding damage over time and leave your roof dripping from a burst geyser.

Cold water also enters the geyser everyday when you use it to shower or bath, how is that different from the cold water entering the geyser when you switch it off?

 

[Dimpie (JIGSAW)]

...the pipes inside the geyser expand when they are filled with hot water...

the last geyser that i cut open had absolutely NO pipes on the inside

 

[voipnow]

Sounds like kwikot have a quality problem and need to do better welding. Switching off saves electricity & people are going to do it more and more.

 

[KleinBoontjie]

I've been doing it, switching off at 21:00 and on at 16h00, for over 8 years now (I believe this geyser is over 10 years old). Our first geyser burst the other day, apparently of age. But i'm worried now, they installed a Kwikot geyser. How is this geysers quality, I mean it got a 5 year gaurentee, is that any good?

 

[noxibox]

They're supposed to be good. Don't discount the possibility that this manager at Kwikot doesn't know the first thing about geysers. Or that he has been misquoted.

 

[Jagtiger]

Solar geyser is not using electricity at all. Will monitor and see what happens. (We switched the power at the switchboard to the geyser off).

If you like a icy cold showers in mornings, then it is a way to go (and way to go to fetch a cold). Maybe a method to conserve water: no man can withstand more than a couple of minutes in chilly water.

 

[noxibox]

If you like a icy cold showers in mornings, then it is a way to go (and way to go to fetch a cold). Maybe a method to conserve water: no man can withstand more than a couple of minutes in chilly water.

Depends very much on your location and type of solar water heater.

You don't get a cold from being in cold water though.

 

[MickZA]

Solar geyser is not using electricity at all. Will monitor and see what happens. (We switched the power at the switchboard to the geyser off).

I've currently got a situation where the major hot water user is away for a couple of weeks and after monitoring electricity usage it seems likely that I could halve my monthly bill if solar heaters are as effective as they claim. What's your experience like to date?

 

[noxibox]

Based on my experience so far I expect to get all hot water from solar heating about 7-8 months of the year. Even during the winter it contributed something most days.

 

[BigAl-sa]

I've currently got a situation where the major hot water user is away for a couple of weeks and after monitoring electricity usage it seems likely that I could halve my monthly bill if solar heaters are as effective as they claim. What's your experience like to date?

I switched on my geyser yesterday for the first time since the end of July. Have just had 2½ days without sun, so I would say pretty effective