Pool Solar Hot Water Heater

ESPHome
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1

Hi Guys,

I am looking for some help to create/recreate a pool solar hot water controller.

The logic seems fairly simple and I am looking for a candidate piece of hardware to use.
I have flashed a few Tuya devices with ESPHome in the past.

The $500 device that I am trying to recreate is this:

You can see that it is fairly simple.

  1. Run the pump for 3 min to get some water flowing.
  2. Check that the output water temp is higher than the input (run for 2.5h)
  3. If the input temp is over 30deg, then turn off

I think I can put together the YAML required, but looking for a good candidate piece of hardware first.
Something that I can solder 2x Dallas temperature probes into, prefer 240v (AU), prefer IP67 rated as it will live outdoors (but somewhat protected).

Does anyone have hardware suggestions?

Thanks in advance.

2

If you can get a certified sonoff TH10 or TH16. That would work, atleast for the pump end. It would still need to be in a waterproof housing.

Try https://www.oikotec.com.au/products

There was a Dallas sensor in a pvc pipe with a battery floating around too.

I have esp8266 running tasmota with Dallas probe, and batteries, solar charge controllers, and little solar panel for mine. I have it setup to sleep overnight, run hourly around sunrise and sunset and then every 10 mins during the rest of the day. I drilled out an end cap and glued the probe in there. The rest is in a Tupperware container lol. It’s not real pretty but works reasonably well.

Not mine, similar idea.

Sonde de température ZigBee - Casaia.fr zigbee one is interesting.

3

I’ve done almost the same as you are planing.

It was working great during the summer! Maximum 38°C in the pool at the evening :sunglasses:.

I’ve used a sonoff TH16 with a 3 temp sensors:

  • at the roof
  • in the pool
  • in the intake pipe

I calculate also the energy of the pump and the energy that the solar heater produce.

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4

I’ve updloaded the yaml file here:

5

This is great!

about 90% of what I wanted is all done, thankyou!

If I am understanding correctly… you are using the ‘climate’ component to trigger the pump and aiming for a 10deg rise in water temperature. Never thought of using it like this!

How/when do you flush the pool heating to test the temperature gain?
I would assume that 1hour after sun up would be an ideal time to run the system for 3 min to test if there is a temperature gain and kick off the process

I have ordered a few Dallas DS18B20 sensors (placed inside a thermowell )
I plan to attach these to a Sonoff Pow R2 (spare pin)
Enclose it in a weather proof container.

6

I messure the temperature at the solar heater on my roof.
No flush is needed.

7

@kortina Did you finish your complete solution? I have a similar setup with 2x pipe installed thermistors reading the temperature of the water coming from the pool and coming back from the roof. I ended up just using a smart plug, with energy monitoring, to turn the pump off/on. I’m working on an automation to pull it all together, along with the weather forecast to determine if it is worth running the pump. I was interested in your timings for when you ran the pump to get the readings updated. Any chance you would be willing to post you final solution? Thanks!

8

I know this thread is a few years old but rather than create a new one I thought I’d add my solution to the same problem that’s been running reliably for me for a couple of years, so everything is in one place.

I’ve got a set of 5 home made panels on the flat roof of my garage and like a previous post I use 3 Sonoff TH Elites sensing pool temp, solar panel air temp and solar water return temp to work out when to run the pump. I’ve documented it here on Github so hopefully helps, I’ve included some custom sensor code to calculate the kW heat output in real-time

9

Thanks for sharing. My current Solar Heater damaged and I’d like to use this opportunity to build it on HA. Any change to use a thermostat card to change the three temperatures, pool temerature, delta outside / pool and pool too hot. Thanks