Solar, HWC, Shelly… Oh my!

Forums › Home Workshop DIY › Solar, HWC, Shelly… Oh my!

1 | 2 | 3 | 4 | 5 | 6

michelangelonz

125 posts

Master Geek
+1 received by user: 40

#3424716 13-Oct-2025 21:56

I wired my Shelly to a contactor to control a 3kW element in the hot water cylinder. The Shelly is controlled by an automation in Home Assistant that measures the exported and used power then turns the Shelly on/off accordingly. I also have a boost mode that turns on at 5pm depending on the length of time the element has been on during the day and at 4am for 3 hours to get to thermal cutout during night rate. Our power bill are probably half what they were with the Solar a HWC control.

CYaBro

4716 posts

Uber Geek
+1 received by user: 1185

ID Verified

Trusted

#3424870 14-Oct-2025 14:01

MikeFly:

I swapped my Shelly Pro1PM for a Shelly Ogemray as I found the Pro1PM got quite hot under load (3kW element)

You can check the status of Shelly products with say an ip address of 192.168.1.123 with http://192.168.1.123/rpc/Switch.Getstatus?id=0 and the temp is listed. Mine was getting up to 60degrees.

The Ogemray has huge terminals as opposed to the tiny Pro ones and obviously higher rated current.

That's pretty normal apparently: https://support.shelly.cloud/en/support/solutions/articles/103000221554-operating-temperature-of-shelly-devices

Ours hit 71 degrees just now.

Opinions are my own and not the views of my employer.

nzrocketman

49 posts

Geek

#3427163 22-Oct-2025 13:49

Has anyone worked out if there is an ideal schedule for the Shelly device for HWC. Mainly the standard ones (Shelly Pro 1PM)

I have mine switch on at 11am and off at 4:59pm daily

CYaBro

4716 posts

Uber Geek
+1 received by user: 1185

ID Verified

Trusted

#3427170 22-Oct-2025 14:40

nzrocketman:

Has anyone worked out if there is an ideal schedule for the Shelly device for HWC. Mainly the standard ones (Shelly Pro 1PM)

I have mine switch on at 11am and off at 4:59pm daily

We have solar so I've got ours set to only turn on with excess solar from 7am-9pm and from 2AM-5:30AM it can turn on and heat up as well, from the grid, or battery depending on how much charge the battery has in it.
That ensures that the water is being heated to the correct temp at least once a day.

Opinions are my own and not the views of my employer.

michelangelonz

125 posts

Master Geek
+1 received by user: 40

#3427737 24-Oct-2025 14:56

nzrocketman:

Has anyone worked out if there is an ideal schedule for the Shelly device for HWC. Mainly the standard ones (Shelly Pro 1PM)

I have mine switch on at 11am and off at 4:59pm daily

Hi there I have mine do solar control between 7am and 4:50pm. Solar control turns on the HWC when the export is above 2.9kW for a minimum of 5min and turn off when importing more than 500W for a minimum of 5mins. At 5pm it does a boost depending on how long the the HWC has been on up to a maximum of 3hours then turns off. At 1am during night rate it does a boost to get it to thermal cutout then turns off at 6am.

Cheers

prob

239 posts

Master Geek
+1 received by user: 50

#3429830 1-Nov-2025 18:28

i do from 10 am to 4 pm every day and 30 min boost from 6:30 to 7 am week days to make sure no cold showers. Also turned thermostat up to 70 degrees C to 'store' more heat. I have a temperature sensor in place but its very difficult to monitor temperature inside cylinder.

Mighty Ape

Shop now at Mighty Ape (affiliate link).

timmmay

20900 posts

Uber Geek
+1 received by user: 5381

Trusted

Lifetime subscriber

#3435945 19-Nov-2025 14:06

Smart Home AU currently have a 20% of sale on Shelley gear for Black Friday.

1 | 2 | 3 | 4 | 5 | 6