nickb800: There are a few options similar to the centameter - usually north of $100 and with a clamp sensor that you normally fit on the incoming phase in your switchboard.

For your needs you could get one of these and clamp it over the phase going to the heatpump or hot water (these will be on a dedicated circuit). I suspect measuring one appliance at a time isn't what you were hoping for, but if you monitored the heatpump for a week, then the hot water the next week say, you'd end up with a pretty good idea of where your power is going.

This will require you to poke around in the back of your switchboard - you can't just clip the clamp meter onto the white insulated cable in your ceiling or going into the hot water cylinder for example, unfortunately.

nova: Do you have a smart meter installed?

We do, and this gives us two things. Firstly, Genesis Energy provide an app which shows power usage broken down by the hour. This is a couple of days behind, but you can get a pretty good idea of what is using the power, I can see when the hot water heating comes on, and when dinner is being cooked.

The other thing it gives is an instantaneous readout of current power draw. It cycles through them, but you can also push a button to got to the screen you want. If you have two people, you can get one person to switch things on and off, while the other monitors the power usage. You only really need to do this once, I don't see why you would do it on a daily basis.

If you don't have a smart meter, you could try ringing up to see if you can get one, or to see if another power company such as powershop would put one in for you if you switched to them.

And one final point, for us, we use roughly 10 KWh of hot water heating per day. We have a 300 litre tank, and this easily lasts us a day. For us, switching to a day/night plan, and configuring our line to only heat the water at night, means that it costs $1 per day to heat water, rather than $2 per day if we were on an anytime rate. It cost us $61 to reconfigure the our meter to day/night and change the boost option, but the payback period was only two months, so it was well worth it.

timmmay: I have a lot of insulation, but it's an older house and it's just not constructed with that in mind. Double glazing, thick carpet and padding, under floor, wall, etc.

I can't change my hot water temperature. I have a brand new mains pressure system and they tell me the only settings are on or off. The temp on the output is controlled by mixing with cold water. I have an insulation blanket over it, but there's apparently not much point with the new cylinders anyway.

wongtop:

timmmay: I have a lot of insulation, but it's an older house and it's just not constructed with that in mind. Double glazing, thick carpet and padding, under floor, wall, etc.

I can't change my hot water temperature. I have a brand new mains pressure system and they tell me the only settings are on or off. The temp on the output is controlled by mixing with cold water. I have an insulation blanket over it, but there's apparently not much point with the new cylinders anyway.

Have you thought about going to a night only rate for your hot water? Saves you about 10c a unit. With only two people in the house you shouldn't run out of hot water. We have a house of 5 and rarely do, but we do have to think about things.