Winter is coming and the last person in my family is stuck with having cold showers.
Does anyone know how these hot water systems work ? Mine is set to heat during off-peak electricity times (around midnight-4am).
If someone uses half the hot water system during the morning, does the tank get automatically topped up with cold water, thus cooling and wasting the hot water that has already been heated ?
Seems rather inefficient doesn't it ?
Wow that's super bad design!
Surely there's a low level switch that the water level has to drop down to before it refills or is it as basic as a toilet cistern where the level is topped up by a float valve?
Time to start sharing shower time OP!
Older gravity fed units worked exactly like a toilet cistern, with a float valve. Nowdays, mains pressure units feed cold water into the bottom of the tank and draw hot water out of the top of the tank, on demand.
The hot and cold water will mix to make the whole tank the same temperature - in the short term, the bottom of the tank will stay cold while the top of the tank stays hot, but not for any really useful period of time, and certainly not until the next off-peak period.
that's why the solar boosters work nicely.
utilizing the power of the sun they heat the water coming into the water heater. so the hot water service doesn't have to work as hard.
I'm thinking I will get rid of my tank and get an instant such as Rinnai infinity 26. Seem awesome, only downside I see if having to wait 30 seconds for hot water to come through.
I found there is not much difference in wait time (depends where the old tank and thence the new Infinity is located i guess) -have had both tank and instant in the past.
The incoming cold water doesn't really mix with the hot from overnight, the different temps keep them separate in the tank. But as you have found when you have used the total capacity it gets cold very quickly.
Is gas connection a possibility at your house? If so, I'd highly recommend an on-demand gas hot water system.
I don't believe I have any gas pipes running near the hot water tank. Is it cheaper to run a gas system, compared to electricity ?
Definitely cheaper running a gas system for heating. Also with an on-demand system, the system only heats the water when you use it, so no wasted power heating water for 8 hours till it gets used.
I switched an old electricity water heater with an on-demand gas when I renovated a few years back and it's been great.
You can also check about getting rebate for replacing the old system, there was a scheme where replacing inefficient old systems with new ones would get a rebate from the government, no idea if it's still around though
Thanks for the comprehensive answers everyone. These on-demand, instant-on, twin element systems sound awesome. In the interest of saving money, I will enforce a shorter shower policy until I can afford a newer hot water system
Have you thought about a reduced flow shower head? That will definitely "stretch" the amount of hot water that you have available, at a low cost. In fact, your energy supplier might give you one for free.
Meh, gas may not be cheaper if the only thing you are using it for is hot water.
Check your electricity bill and see how much you are paying for off-peak (i.e. hot water), now compare that to the amount of money you would be paying just to have the gas service connected (i.e. the service charge). In our case, we pay about $3 more for all the electricity used to heat hot water than we would pay just to have the gas connected and use none. Once you take into account the gas usage, gas is more expensive than electricity for us.
If you are running out of hot water it means that your hot water system is too small for what you use. You could either use less or get a bigger system installed. If you are replacing your system, you may want to look into heat pump technology and see if that is suitable for you.
Heat Pump like an air con in reverse.Sill need electricity.
Gas or Electric Constant flow still need electricity. Can use hand gas stove lighter if power is out.
Solar Hot water. still need electricity as water must reach certain temp to kill bugs that can kill you.
Off peak tank can be gas or power.
Combustion stove need axe. Not good if upset partner.
Underground thermal storage cooling and heating. use for house and hot water. Needs power,
It comes down to budget and how much is needed and add 25%. Use the calculators the selling web sites have.
Goodluck there maybe other options that could be offered.
If I were building especially with slab or like where I live having underground rivers and aquifers I would use the thermal storage with solar. But having [last year] just gone through the replacement of 25 meters of sewage,and 15m storm water, pipes I would hate to think what the yard would be like if had to retro-fit.
Tank
still need electricity as water must reach certain temp to kill bugs that can kill you.
Eh?
Dr Karl reported on talkback 72 degrees.
https://au.tv.yahoo.com/sunrise/factsheets/article/-/8961167…
OK, with you.. sort of..
Solar Hot water will be safe.. It's the long term storage at warm temperature that will allow Legionella to grow.
The one off day or even week that a Solar hot water service doesn't heat the water past 60 degrees would only barely increase the already very low risk of catching Legionnaires Disease from your Hot Water.
All solar systems have a backup system anyway to cater for those days.
Yes, that's how they work.
You can get twin element units that have a boost switch that allows you to heat water outside of the off-peak period.