Power meters, how do they work, help please

Forums › Home Workshop DIY › Power meters, how do they work, help please

mrhaboobi

195 posts

Master Geek
+1 received by user: 9

#323986 12-Feb-2026 09:33

This might be a stupid question. Sorry. Google didnt answer.

Im moving properties, in our current property we have Day/Night EV plan with Meridian. Hot water heats from 9pm -7am ( or in that window ).

I also have a timer on the fuse board with an external switch that allows me to do a day time boost when i want. If we run short of watch i push the button, it runs for an hour and away we go..

Im moving to a new property and I'm wanting a similar set up. I'm looking at this option

https://eurotechnz.co.nz/products/bluetooth-hot-water-cylinder-control-kit?srsltid=AfmBOoqgtbuPvzXg8FBRVm7JrhV2Wo55dP_YP23kk16KQkE-PHmOOc0U

However this is installed at the wall connection next to the cyclinder so is really just a timer to turn on and off, and I'm not clear how it would be used as a boost?

Maybe my quest is more about how power is supplied to homes. My niave understanding is that HWC is normally connected to a separate channel which is normally wired to night rates so that only power is supplied between 9pm - 7am? outside of this you would not get power to the cylinder( unless you had a day time boost option? ) . To do so you need some form of change over switch that would sit on the circuit board and flicking that would switch you to the Day Channel and you'd then get power to the cylinder. Is this how it works or does a house just get power, and anything you use between certain time windows is just charged at a certain rate? therefore the HWC would need a 9pm - 7AM timer and if i did want to boost i could during the day..

So really just trying to get my head around it better, so that i can talk with the electrician and look at the correct power plans.

thanks

wellygary

8810 posts

Uber Geek
+1 received by user: 5287

#3460880 12-Feb-2026 09:41

" . To do so you need some form of change over switch that would sit on the circuit board and flicking that would switch you to the Day Channel and you'd then get power to the cylinder."

Which is exactly whet you have now with your "boost timer" -

You need one of these otherwise when the Hot water is off ( formerly known as ripple control) the circuit to the HWC is dead, -

Your bluetooth device requires a live circuit, so won't work between 7am and 9pm)

mrhaboobi

195 posts

Master Geek
+1 received by user: 9

#3460881 12-Feb-2026 09:44

wellygary:

" . To do so you need some form of change over switch that would sit on the circuit board and flicking that would switch you to the Day Channel and you'd then get power to the cylinder."

Which is exactly whet you have now with your "boost timer" -

You need one of these otherwise when the Hot water is off ( formerly known as ripple control) the circuit to the HWC is dead, -

Your bluetooth device requires a live circuit, so won't work between 7am and 9pm)

Thank you, so bluetooth at the wall is not what i need. Can i ask ( if you know ) how do companies handle things like 3 hours of free power etc. in theory you can set this to be any time you want? i assume they are not using day night rates as such and therefore not multiple channels, they just change their billing to account for a cheaper rate during the time you specify?

Thanks