Installing a geyser timer

Ok with so many people saying it doesn't save cash etc... I wanted to try a few things. I don't have a timer as yet... So literally flipping my switch manually.

Geyser is a 3kw / 150l geyser and these are what I've seen :

Option 1 : Running 24hrs a day (like most run a geyser) , I used 12 units in a day.

Option 2 : I'd flip off at 7am and flip back on at 10pm. So it was active 9hrs in the day. I used 8 units

Option 3 : I'd flip off at 7am and flip on 7am the *next* morning. So the geyser cooled over 24hrs. I ran it for an hour or two before my shower, and repeat. I used 12 units.

So running 24hrs and 1 or 2hrs, was the same consumption and no saving. But running 8 or 9 hrs saved a chunk
 
Dolby said:
Ok with so many people saying it doesn't save cash etc... I wanted to try a few things. I don't have a timer as yet... So literally flipping my switch manually.

Geyser is a 3kw / 150l geyser and these are what I've seen :

Option 1 : Running 24hrs a day (like most run a geyser) , I used 12 units in a day.

Option 2 : I'd flip off at 7am and flip back on at 10pm. So it was active 9hrs in the day. I used 8 units

Option 3 : I'd flip off at 7am and flip on 7am the *next* morning. So the geyser cooled over 24hrs. I ran it for an hour or two before my shower, and repeat. I used 12 units.

So running 24hrs and 1 or 2hrs, was the same consumption and no saving. But running 8 or 9 hrs saved a chunk
Click to expand...
You'll see more benefit during winter.
I'm in Gauteng, the winters here are much colder than the east coast.

I switch my geyser off at around 9pm and switch it on at 7am, so that it's off during the night when the air temp is low.

I can tell you for a fact I save alot!
 
Trust|Nobody said:
You'll see more benefit during winter.
I'm in Gauteng, the winters here are much colder than the east coast.

I switch my geyser off at around 9pm and switch it on at 7am, so that it's off during the night when the air temp is low.

I can tell you for a fact I save alot!
Click to expand...

I'm agreeing with you - but it isn't shorter is automatically better (like I thought)

When I went from 24hrs on to 8hrs on, I saved 30% - so I thought going from 8hrs to 2hrs, would save even more. But 2hrs on uses the same power as 24hrs on
 
Trust|Nobody said:
You'll see more benefit during winter
Click to expand...

I suspect 2hrs per day, would use more power than 24hrs in winter ... as the geyser has had more time to cool, and will work harder in those 2 hrs than in summer
 
Dolby said:
Ok with so many people saying it doesn't save cash etc... I wanted to try a few things. I don't have a timer as yet... So literally flipping my switch manually.

Geyser is a 3kw / 150l geyser and these are what I've seen :

Option 1 : Running 24hrs a day (like most run a geyser) , I used 12 units in a day.

Option 2 : I'd flip off at 7am and flip back on at 10pm. So it was active 9hrs in the day. I used 8 units

Option 3 : I'd flip off at 7am and flip on 7am the *next* morning. So the geyser cooled over 24hrs. I ran it for an hour or two before my shower, and repeat. I used 12 units.

So running 24hrs and 1 or 2hrs, was the same consumption and no saving. But running 8 or 9 hrs saved a chunk
Click to expand...

Have insulation on the pipes?
Mine for the month so far looks like this and never see 12units a day.

989924fc22270733c88ced32ba2f0706.jpg
 
Dolby said:
Ok with so many people saying it doesn't save cash etc... I wanted to try a few things. I don't have a timer as yet... So literally flipping my switch manually.

Geyser is a 3kw / 150l geyser and these are what I've seen :

Option 1 : Running 24hrs a day (like most run a geyser) , I used 12 units in a day.

Option 2 : I'd flip off at 7am and flip back on at 10pm. So it was active 9hrs in the day. I used 8 units

Option 3 : I'd flip off at 7am and flip on 7am the *next* morning. So the geyser cooled over 24hrs. I ran it for an hour or two before my shower, and repeat. I used 12 units.

So running 24hrs and 1 or 2hrs, was the same consumption and no saving. But running 8 or 9 hrs saved a chunk
Click to expand...

how were you measuring it? overall on your prepaid meter? or with a power meter?
 
Pho3nix said:
Mine for the month so far looks like this and never see 12units a day.
Click to expand...

Sorry - I meant my overall use was 12 units/kWh.

So overall power consumption with same appliances I use 12 units (24hrs geyser running), 8 units (9 hrs geyser running) - and back to 12 units (2hrs geyser running)
 
Trust|Nobody said:
This portion doesn't make any sense to me from an energy balance/consumption perspective.
Click to expand...

That was how it really worked - but it does make sense to my non engineering mind :

After 22 hours sitting off, the geyser is at 25 degrees and needs to warm back up to 60 degrees - so it''s working harder going from 25 to 60 (more energy required)
With it being at 8 hrs on, the water never gets to 25 degrees - probably only manages to drop to 40 degrees ... so it really only needs to go from 40 to 60

* I'm no engineer
* I'm making up the temperatures - but that's the concept
 
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Dolby said:
Prepaid - so I check my previous 24 hour period (and have for the last 1 month+).
Click to expand...

ok but in fairness that isn't fully comprehensive, but either way i am on the side saying that these things are generally not worth their money unless under certain conditions
 
Steamy Tom said:
ok but in fairness that isn't fully comprehensive, but either way i am on the side saying that these things are generally not worth their money unless under certain conditions
Click to expand...

It's not 100% accurate and tested in a lab environment - but it's real consumption observed. And to me, it makes sense that the more higher differential, the more power/energy needed to get it back to the 60 degree. I bet that in the first case, even the 3kWh geyer is running at 1kWh (more frequently, as it needs to go from 45 > 60).

The same 3kWh geyser is using the full 3kWh in the last example to go from 20 > 60.

As you say, certain conditions - I'm single (ie only one shower at the same time) ... If you have a family with kids showering 6am ... you at 8am ... and wife at 9am - then yea, it won't work.

Blur arrow is when the thermostat kicks in :


1555751485052.png
 
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This seems right to me ... and what I wanted to show.

1555752077415.png
 
As previously stated.
1. The quality of the geyser is the most important factor. Regardless of the quality, a Geyser blanket is worth investing in because it reduces the heat loss to the environment.
2. Insulating the pipes (ALL of them, cold and hot water) leading to and from the geyser reduces heat losses. Especially if steel or copper, but also helps with plastic pipes.
3. THEN as Dolby has demonstrated, you have to understand your specific water usage patterns and adjust them accordingly.
4. Now you can play around with timing as Dolby has indicated to find the combination that leads to the best savings for YOU. What works for you will not work the same for someone else.

And yes it is about the temperature differentials. Hence why there will be a winter setting and a summer setting.
And yes the idea is to keep the temperature differential as small as possible.

Only then will you be able to optimise the savings.
 
Trust|Nobody said:
I returned the MajorTech timer and got an Ellie's BPFSGT3-P timer.

The Ellie's fits directly into the DB rail without any mods needed. And the Ellie's instructions is much better written than MajorTech's. I've attached them here.

I'll fit later today
My first electrical DIY.


View attachment 648052View attachment 648054
Click to expand...

Good luck! Not that difficult to do! About the diagram --- more descriptive but essentially the same as the other supplier.
Note the battery life. Believe me it hardly ever lasts much longer than 3 years.
Next, the problem with those timers is the same as with the Major tech ones. The contacts burn and fail far too quickly.
The timing options are really useful.
 
For those of you that might want to understand geysers better, here is a reference that encompasses most of the concepts and combines it with a relatively simple scientific explanation. The reference details what can be expected in terms of savings using timers, as well as why profile devices such as geyser wise are a really good idea.

http://www.scielo.org.za/pdf/jesa/v23n1/06.pdf

Timers set and used properly can achieve a 25 - 30% saving in energy costs.
 

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