Geyserwise Timer on HA

Does anyone know if it is possible to switch one of these, Geyserwise TSE, timers with HA?

I would just want to turn it on/off through HA. Thinking that surely it should be possible to just open it up and link the “power” button with a relay that would trigger it?

Or have anyone done something different?

Basically I would like my geysers to come on when there’s additional capacity in the PV, and off when there isn’t. At the moment they are on from 12-14:30 (two geysers staggered) and it is typically fine, depending on the day, I can already start running them at 10:30/11:00.

I use a contact between the geyser wise and the geyser. I for a “backup” the geyser timer is setup to only come on after 9h30.Then the automation system handles the rest. So should the system fall over the geyser will at least only come on during day time rather than in the middle of the night. Been doing this now for Four years and no issues , yet


Not much you can do with the TSE. Comms protocol not available, and seems well obfuscated.
I ended out desoldering the MCU and adding my own controller to give it a modbus interface:


Thanks for the suggestions. I guess if there’s anything that needs to be changed (electrically) from the current setup, I’d rather figure out a way to get an electrician to do it. Happy to play with my pool pump, but I’d rather not mess with this stuff in my roof. That “what if I start a fire and the insurance don’t pay out” is a bit too big a “what if” for me…

I have a similar problem with my heat pump. The controller is also not accessible.

So the easiest solution I could come up with is to add 'n extra relay that you can control from HA (like the
CBI Astute or a Sonoff) in serie to the power. You then schedule the Geyserwise for a large time range and then HA will manage the extra relay.

Both have to be closed for the geyser to work. So if the Geyserwise stop (temp reached or schedule) the geyser will stop. If the HA relay stop (not enough PV) the geyser stop.
You just need to have a rule in HA to say that by 4pm the geyser is always on so that it can heat if there was not enough PV during the day.

I have not implemented this on my heat pump yet. Somewhere I read that you can’t just trip the heat pump power. It has to stop from the controller. Not sure how true that is. Still trying to get to the bottom of it.
It should no issue on a normal geyser element as that is pretty much how they work.

Jip, agreed that it should not be an issue on an element geyser. Guess I should be able to contract an electrician to install a flashed Sonoff for me.

Technically those POWs should be able to handle my Geyser’s current draw, but I’m not super comfortable with those contactors. They really put some crap push stuff into those POWs to the point where I actually don’t use the one I bought, just the basics (at least I can screw them down).

Maybe I should try and rig together something using my old pool pump timer. It has nice and fat screw-in contactors and a 30A rating. Would just need to jiffy something together to switch it… But then getting an electrician to install it would probably be out of the question as the product would not be “certified”?

Regarding your heatpump - My extremely laymans “feeling” around tripping it is that it might not be a good idea. Thinking about how an aircon “powers down”, something similar might be required. Perhaps the compressor should release or something weird like that… I just don’t like “tripping” things with moving parts.

I agree.
It should be able handle some tripping as the power can trip “normally”, but doing this potentially a few time a day might not be the best idea.

Just a point to share.

Having 2 x 150l geysers on those Geyserwise timers, I scheduled one to start heating at 10 am - heated by 12pm - the other at 1 pm - heated by 3 pm - and extended the times on both until 5 pm to keep hot due to oversupply of solar.

Geyser 1 is a verticle B+ rated outside one, the other a cheap horizontal outside geyser which loses temp. When the cheap one pops, will get a 2nd verticle B+ rated one.

Should have gone for a 400l geyser for both homes … so we learn.

Anycase, it fits 100% into my solar production, and if there is insufficient solar, well, that is just tough because hot water equates to happy females which in turn means they are not on anyone’s case … the cost (cents on the rand per month) for that precious peace becomes a negligible moot point. :wink:

The KISS principle in other words.