Hi there - we are new to the solar hot water world, I'm afraid, and I'm not sure about how to use the manual booster option we have with ours (1980s solar system)! What happens in winter in Canberra (and now, when it's cloudy and cool?). We find we need to turn the booster on after a few cloudy days - are you supposed to only have it on for an hour or so and then turn it off? I'm finding conflicting information on the web. People are saying that the booster is the equivalent of having 1000 kettles turned on (or something similar) at once so you should never have it on any longer than an hour - does that sound right? Many thanks, Christine

I hadn't heard of the 1000 kettles.... ours is on a timer and in winter we have it set to come on an hour before we get up, so ensure hot water for showers.

Cold weather doesn't matter much, but cloudy weeks like this one, you will need th booster.
It is more about when you choose to boost I think.
Eg - don't boost when I would have thought you'd need it for more than an hour at a time.

The booster is relly just like a normal hot water heater, except that it heat the top of the tank first, so it is expensiv if that is the only way you heat your water, but for a few cloudy weeks a year I wouldn't worry about it too much.

Hi Toadflax - I am nearly 2 years with solar hot water and still figuring it out. 2 days of cloud definitively equals booster. Our booster is on a timer set to go for 2 hrs at 3am and 3pm. The installers set it up that way. We also have a manual switch.

But the thing about this time of year is that the cold weather has an impact. The last technician that came to us said that the system basically doubles the ambient tempreture. So days under 20C are not going to be enough to make hot water (I like the water 38/39 degrees).

I just rang the shop to confirm this and they said yes. And told me to switch the booster on autumn and then off about september. This is pretty much what we did last year.

And as you probably know, the booster takes power at peak rates. So it is expensive. I might try one hour twice a day and see what happens. We have 2 adults, 1 toddler and 1 baby. I am also going to ring our electrician to see if it can be hooked to the offpeak meter. Our power provider (who I also just called) said that it may be possible but because I am in NSW offpeak times are not consistent because they are manually switched over. The ACT has consistent times. Confused yet?

I have been learning through experience.

It is driving me nuts

Thanks very much Seepi and Zaza. Sounds like I'll have to do some experimenting. Yesterday I turned it on for a bit before the kids bath (around 5pm) and turned it off, and this morning the hot water lasted for about 1.5 showers (of course, I was the 0.5 shower!). Might turn it on briefly in the morning and see what happens. I miss the instantaneous gas we had at our old house!

You can just leave the booster on permanently if you want to never have to think about it. You will still save money on hot days.

You will need to turn the booster on in the mornings as soon as you get up if you want lots of hot water on a cloudy morning.

If you turned it on for the kids baths at night, they would have used up that water, then the system cooled all night, so this is why you had no hot water left in the morning.

What you are getting is free hot water of an afternoon, due to the sun. The optimal thing is to do lots of hot washing, or even bath the kids in the afternoon.