ShyteZA

A normal 200L geyser will use about 15-20kwh per day for a house of 4-5 people using hot water. The thermo tank uses 4-5kwh. So I am using about 1/3 energy to heat up and maintaining the same amount of water. A 750w heatpump will deliver only 2-3kwh of heating per hour so the water takes longer to heat up. This is an issue because everyone baths/showers between 6 and 8pm which doesnt give the heater enough time to bring the water back to temp for the last 1 or 2 people. This is where the gas geyser assists so that everyone has hot water and also reducing both gas and energy consumption. The main point is endless hot water without the drawbacks of the issues with gas geysers while resulting in lower electricity consumption and lower gas consumption. While implementing a gas and heat pump solution together is a costly exercise upfront, families that have a gas geyser installed looking to save on gas should consider integrated heat pump solution thats feeds into the gas geyser. Their lower energy consumption is also easier on your solar system where the gas geyser only picks up the slack when there are too many people want to use hot water simultaneously.

Been using gas geyser for 10 years. Had to replace the first Atlas geyser 4 years ago because PC board blew and they didn’t have parts. My usage is about the same as yours. 6 weeks on a 48kg during winter and about 3 months during Summer. Decided to find ways to save on gas and wasn’t keen on the solar geysers with the evacuated tubes. I decided to install the Magneto Thermo tank in June 2025. It has a heat pump above the water tank and can be installed standing upright outside instead of having it in the ceiling. Currently it feeds the gas geyser 60C water and gas geyser will only go on when water drops below 50C. My 48kg during Winter is already lasting 2 months and hasn’t finished yet. Will see how long it lasts before changing it. But what is better is that I don’t have to wait as long for hot water to some of the bathrooms. Also one of the biggest issues I had with gas geysers is that if you mistakenly close the tap, you get a brief session of cold water before it gets hot again. In winter that is an issue for the wife. Also with the smaller taps, no issue with slower flow rates not able to activate the flow rate sensor on the geyser as the water is already hot coming from the Thermo tank. But the best thing is the heat pump is 750W and runs about 5-6 hours a day for me. So that is 4-5kWh of electricity to heat the 200L tank and this is in winter. I would imagine this translates to a COP of about 3. Should be better with summer as there is more heat to extract from the air. The main gripes with heat pumps is mainly the longer heat times compare to a heating element. But this is solved by supplementing via the gas geyser. If I reduce gas consumption to about 2X48kg per year, effectively saving about 6 bottles per year, R1300 per bottle is about R7800 per year. Break even will be about 4 years.

The main illustration of the diagram is to connect the batteries in diagonal. Ie the positive terminal of the last battery and the negative terminal of the first battery to go into the inverter. This is done so that the batteries drain more equally. We cannot see if this is done on the installation