Water heating

[Tradie]

I have been looking into solutions for water heating, after a call from a customer indicating that the water is cold every night when it is time to shower.

I started scratching and doing a lot of research.

What did I learn,

No matter what system you install, be it heat pump, solar, geyser with Ai or the size of the element, you have to take a step back and look at the fundamentals, as with anything.

I believe what happens in most cases, people read all the BS on social media and sale pitches, with promises of products that will not only reduce your monthly bill, but offer instant hot water, without taking a step back and looking at the whole setup, no matter the modification or Ai, you still going to be sitting waiting for the hot water.

I climbed in the roof the other day and noticed the customer had fitted a geyser blankets over the geyser, and asked if they had resolved the water heating issue and got the response I expected.

By the way this goes for elctrical installations, if you dont step back and look at the entire installation as a whole you might get lucky and resolve the issue.

[IanF]

I moved into a much smaller house in a complex with a gas geyser. Once you figure out how to adjust the temperature on the mixer it is great. Our shower is about 4 metres from the geyser, so you wait about a minute for the hot water. It has a battery for the ignition, so power outages are no problem.

[Derlyn]

Electric showerhead. 10 years now. One element replaced R245. Less than half the running cost of a gas geyser.

Only down is no hot water during loadshedding, but we work around it.

[Tradie]

What I have learnt:

The distance from the geyser to the tap is critical, in fact the most important factor.

Lagging hot water pipes is essential if you have long runs.

If you have 1 geyser and over 10 m of hot water piping, a circulation pump should be considered.

You can 500 litre geysers, with 10 kw elements, if you have a long hot water line, no circulating pump, and cold water feeding the geyser, you going to be battling with hot water.

With the crazy municipality increases every year, the utility bill has already overtaken my monthly bond payment, I pay more to the municipality for light than I pay for my bond every months, I wont even talk about food bill.

Instead of whining about it, I need to figure ways to reduce the time the water runs and how much power is used to heat it.

Solar would be nice, but its is not going to happen anytime soon.

I am focusing on implementing small fixes which are cost effective.

[Tradie]

I am thinking out load.... feel free to point me in the right direction f you have a better solution.

I need to warm the water before it reaches the geyser, what do we do, fit

1/ solar water heater on the roof,

2/ heat pump or

3/ Electric solar panels, then use any excess to run stuff in the house (talking a small system)

Replace my old 45 galleon drum looking geyser, with smaller insulated geysers closer to the outlets.

The kitchen being the longest run at present, fit a small under counter unit.

The bathroom and ensuite, are pretty close, fit a 100 litres between them on the wall outside.

For the shower, get something like a shower head, which makes sense because it is instant heat. I found that showers with a lever are way more practical than taps, because I shave in the shower (saves blades, but waste water) you can push it off then pull it back to the same location (you get to know the setting) when you are ready to rinse off.

[Tradie]

Water temperature, without knowing the temperature of the water in the geyser, its like trying a ball with blind fold on, the reason I am considering one of the devices as mentioned in another thread.

What I would like to do, is set the thermostat to cut off at 70 degrees and have a way to control the temperature during the day and change it in summer and winter.

You dont have to heat the water to 50 or 60 or 70 during the day, and it would be way better if one could schedule the temperature and time.

My geyser has always been set to 55 degrees, after the incident yesterday, I turned it up to 60 degrees, so now it takes longer to heat up, and wastes more electricity.

I fitted and ASC, linked it to HA , which now not only allows me to view the total usage per day, but now I can also see when the unit switches on and for how long.

This is going to allow me to attempt to control the energy usage a little better.

The more I think about it the more I think it is time to find a way to preheat the water before it gets to the geyser, because the cold water mix is not the smartest thing to do.

In winter we make fire, having a coil wrapped the chimney would be a smart way to perheat the water in the evenings, much like donkey, just that you know warm the house and heat water.

Garden refuse generates heat, so if you built a radiator of sorts would warm up the water.

Ther emust be easy ways to create heat from things already being used around the house, like and aircon/ heat pump.

[Derlyn]

I'm a fundamentalist and I've been through this over and over.
One can have as many timers, controllers etc on a geyser circuit, but if you are heating more water than necessary, you are wasting energy.
The secret is to heat only what's necessary.

There is only one way of achieving the above and that is instant water heating.
There are 2 ways of doing this, either electric or gas.

Now lets take a 5Kw electric unit is going to cost 5 units @ +- R4 per unit = R20/hr.

A small to medium gas geyser uses a minimum of 1,5Kg's of gas per hour @ +- R32 per Kg. 1,5 x 32 = R48/hr.

If it's a saving on your electricity bill that you're after, an instant electrical water heater on the shower is the answer.
Nothing beats it.

The cheapest way of having hot water for washing the dishes is to boil a kettle of water. Nothing beats it as far as price is concerned.

Even a donkey is more expensive if the price of wood is taken into account.

[Tradie]

Having a shower this morning made me realise, the location of the heater is important but as important is the temperature and control of the temperature.

If your shower is too hot and you have to add cold water, you wasting water and electricity, but the problem with modern day water heaters, you dont have a way to control the temperature, just a cut off thermostat, without climbing in the roof or under the geyser outside.

you could use an ASC or ASI to control the temperature, but then you would have to bath or shower at specific times, it just means another thing I have to worry about, hence the reason for looking into home assistant and AI without adding another monthly bill/subscription)

The best solution would be a temp probe and solid state relay connected in series with the thermostat (safety) to your geyser, which is linked to an app and a screen somewhere where in the house, using resources like the sun to reduce costs and optimise the system.

Why am I wasting my time with this, because my utility bill is officially higher than my bond, subscriptions and medical aid (dont get me started with medical) , catching up just as fast, I need to find ways to cut back my utility bill by around R4000 per month, which now makes it worth while looking into the highest consumption. water and electricity.

I need to find a way to create an overview of everything going on within the property connected to a local network (no subscriptions), I dont mind paying extra for the device if it can link to a local network and not need the internet, but need to also be aware of products for sale that work for a year or 2 then require a subscription or stop offering support, as we learnt with a certain brand.

[GCE]

Quickest way to have hot water and reduce electricity bill is to install Solar
Start with a 5 or 6kw system - Depending on usage an 8kw is ideal - prices have drop tremendously , install one string for now and the 2nd string as phase 2 , battery as phase 3 and heat the geysers at mid day to 65degrees

I sit with 2 geysers , main house and flat - Run them staggered between 10H30 and 15H00 - During summer I don't need to heat again until next day - During winter I top up at night with 2Kwh .

When I was on prepaid meter with solar - Was using +/-900 units(according to inverter) and only having to purchase +/-230 units - Average electricity spend went from R3K to R750 .Now on TOU and sitting at R500.00
System operational in Sep 2023 Until end Aug 2024 - 12 months - savings R22K
from Sep 2024 to end June - 10 Months - R26K
With the new increase the savings are now around R 3 500.00 a month

Reckon my savings will be around R55K in 2 years - Half way there to system repaid

Graph of shortest day and a longish day

[Justloadit]

I suggest using a Geyserwatcher solar heater designed by me and sell I as a product. Connect 3 panels around 1500W solar and set the thermostat at 65°C, any higher and the heat damages the rubber gasket over time.
It also has a mains input, which over rides the solar input. Use a Sonoff POWR316D with a temperature probe. Use the app to set up a timer if you like to say switch on at 5 to 7 PM to control the temperature at say 50°C. The solar should heat the water to 65°C during the day, on the off day it does not then mains will come in and heat to 50°C.

If you shower in the morning, you could also set the time to run say at 4 to 5 in the morning at 50°C, and in the case that the temperature is low, electricity is used to bring it up to temperature. In this way you may or may not use 3 to 6 units a day in a worse case scenario. It is also about scheduling when every one has a shower, to make use of the convection movement of water in the geyser as it is being consumed. You stop, and the cold water then starts to mix and drop the over all temperature in the geyser.

My website www.apricusaqua.com is being rebuilt so you can not get to a brochure. (Date 17/7/2025 should be up by the 30/7/2025).
Geyserwatcher leaflet rev 3.pdf

There is a discount for installers and resellers. Contact me if you are interested.

By the way the Sonoff shows temperature on the display ad has a manual over ride as well if you need to heat up at any time, and also you can set the default temperature to heat up to.

[GCE]

I keep looking at the separate geysers systems like Justloadit and come back to a different thought process

Generally , and correct me if I'm wrong , the pricing comes in at around 16to20K for a system installed and sometimes roof space becomes an issue with trying to fit panels for various systems.

By going with inverter and panels you have the advantage of utilizing the time periods when the geyser is not on to supplement other electricity items , swim pool , stove etc and feed back to grid for credit.
We don't put the geyser on the load side of the inverter we use the grid side and feedback to CT setting

We have a client now that has 3 geysers , swim pool , steam room , gym, 2 stoves electric and 1 stove gas and works from home

To have used a geyser system would have looked at 3 geysers with 3 panels each - 9 panels spacing gone .

We utilized the money that would have been spent on geyser systems to supplement inverter pricing and stuck 26 panels , 2 x 8kw inverters ( to get extra MPPT's due to roof angles) and 30Kwh battery storage .

Then I sit with my own one where a geyser system would give me extra from PV system to feed back and zero my account - But if I take that money and spend on a 5kw + 1 string of panels it will cost about 30% more but will recover the money quicker feeding excess back to grid

Tomorrow I may think differently

[Justloadit]

The issue here is that you have to manage when the best time to switch the geysers on.
Lets take the example of the 3 geysers, each with a 3kW element, total 9kW, they need to be staggered for 3kW at a time or else the feed back solution is not going to put a dent on consumption.
With the independent solar geyser solution, all geyser will be heating as long as there is sun radiance, albeit it at lower power levels, but remember that the water acts as a collator of energy, so it may take 4 or 5 hours to heat from 30° to 60° C, but there is no burden on the home inverter system. It also has the advantage that each geyser can be individually switched on mains if required using a temperature/Time switch like Sonoff THR320D

[Tradie]

I want to start small, I have a small 45 gallon drum looking geyser in my house 150 litre which now has a brand new 2 kw (8.9 amps) porcelain slide in heater, which can still run with my 5 kw generator if I need hot water. I have also installed a brand new CBI ASC (because they generally last, however the only one that has failed, was sent back to CBI to find out why it failed, I was told it is out of warranty and no report, as requested, I must say I am a bit disappointed, if anyone at CBI is aware of a ASC, it would be nice to get some feedback)

I also have a 200 litres 4 kw element, which has never been connected (since it was installed 16 years ago) , up in the roof of the garage, I dont know if it will work, maybe the drum has rusted, so the plan is to maount the geyser on an outside wall, if it pops, I can just replace it without affecting the roof.

What is going on in my head, after doing a little research, and trying to figure out a smart way to generate and maintain hot water without it costing a kidney.

1/ I need to find a way to heat the water and the most economically way possible, be it a fire under a donkey, solar panels, feeding an MMPT, DC direct or a solar water piping on the roof.

2/ Figure out a way to store as much hot water as possible, without loosing the heat, by insulating pipes, using decent quality geysers, that have built in insulation around the drums.

3/ Control and manage the system using the technology available, like mini computers, solid state relays, circulating pumps, temperature probes and thermostats. You can only mange and control what you can measure at the geyser.

I started with the ASC, using an ASC to manage your water heater, within the first week, we identified the most common problem using timers, identifying time of use, when do you need the hot water and when is it most commonly used.

Thursday, people in the house decided to shower earlier than the normal time, resulting in a cold water bath. The person responsible for the control of the hot water which resulted in a cold bath, is the one who collects the most. Everything is temp. bypassed.

We take a step back at look at the entire water heating setup, first thing we identify, why there is no hot water at 16.30 in the afternoon, the home exec is back from leave, and we have identified that she only knows how to use the hot tap for everything, and I mean everything. First challenge identify and educate.

Then we find that the kitchen hot water tap is the most used tap in the house between 7 and 16.30 in the afternoon. We need a solution for that hot water tap, maybe a small under counter quick heat undercounter solution. Some might say gas, my concern, have you ever tried to heat water on a gas stove, if not, try it and share your experience. The kettle makes hot water much faster.

the next step is the bath, I know, I should remove all of them, they waste water and electricity trying to heat water. Lets step back and think about it a little, if you going to use a circulation pump to keep the insulated pipes water, why not remove the bath and pipe the hot water that is circulating around the bath, the bath will always be warm. Everyday at 15.00 a solenoid opens and allows the hot water to circulate around the bath, have a thermostat to control the heat and shut the solenoid when the set temperature is reached. That saying happy wife happy life, you wont even need candles

[Derlyn]

Simplest and cheapest are instant hot water units with gas geyser as backup for when there's no electricity.

Simple and cheap.