We chose the Apricus 315L electric boost hot water system, which uses evacuated tubes.

We're fairly happy with the system so far, but not the way it was installed. We've been in the house since the beginning of winter, early June.

The system was installed in the only part of the roof where they are shaded in the early mornings (for at least 8 months of the year). We have a large expanse of north facing roof, and a small bit that juts up where the celestory windows are from a loft area. The tubes were installed directly to the west of this highest roof area. I don't know how much this effects their heating first thing, but it must be quite a bit in winter because it's at least a couple of hours of direct sun it blocks. If I can move them at some stage I will, but apparently they should be as close to the hot water tank as they can, so not sure if that will ever be possible.

I had misunderstood how the system was set up by default. I had read a lot on forums about having the boost that you could set to whatever time suited you - say between 3-6pm in the afternoon so that it would only come on if the day had not been sufficiently sunny. I had thought it was something you did in the control panel. Unfortunately it's not, it's something you have to get your electrician to set up at point of installation - put a timer switch in the electricity box. I didn't realise this til we were in the house for a few weeks and I got around to reading manuals of things.

So our electrician put the electric boost on Tariff 33, which in Qld is available for at least 18 hours a day. What this means in practice is that every time the Tariff 33 comes on, it checks the temperature of the tank, and if it's not at least 60 degrees, it boosts it. I don't know how often it boosts it during the day and night, specially in winter, it could boost several times a day for all I know, when it really only needs to boost once a day (for health and safety reasons).

I am thinking about getting our electrician to install the boost timer, it would cost over $200, so I'm just waiting for my next electricity bill to see if it's warranted.

Our first bill was for the three winter months since we moved in and our hot water component usage was the same or a bit more as my parent's who live next door, who have an electric system on Tariff 31 (super off peak) with about the same size tank. We probably use more water than them, having two small kids and they being frugal pensioners), but still, it made me a bit worried. I spoke to someone at Apricus to see if there was something wrong with our setup, but they seem to think that was a reasonable usage of power.

I don't know though, as our winters, though very cold at night (-3 or -4 most nights) are very sunny and ideal for water heating during the day.

I was thinking about manually turning the boost on when needed, but decided to leave it as is for this next three months and see how it goes for the next bill. If the usage of the boost is still high I'll probably get the electrician in to put it on a timer.

I'm also planning to build a little shelter around the tank to counter heat losses at night in cooler weather.

I'll update this post when I get the next bill.

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