Cylinder immersion heater

[Too Late]

Hi all
Doing a large house build. I am at the moment trying to automate as much as I can.
One thing I have put off doing is wiring in the immersion heater into the cylinder.

What are people's thoughts.
Element is wirer to the stat. Stat is wired to a 20am DP switch.
Due to the draw I need to the add a contactor to switch on when I need the immersion heater

Question is will I ever use the element over gas?

[Snow and Rocks]

Always worth having as a backup - you never know.

Probably doesn't justify the effort of including it in your automation efforts - if your boiler is broken, just leave the immersion switched on and it takes care of itself.

[Too Late]

That's a good point.
Not including just means I use the 20dp switch instead.

[JoshSm]

Got any solar where you might choose to dump some excess via the immersion?

For the cost of a 16/20/25A rail mount contactor I'd probably just do it anyway.

[.:ian:.]

On octopus agile I always flick mine on when it's negative pricing, should get a high current wifi switch so homeassistant can do it, but it would probably never pay for itself

[biggiles]

We only use the immersion in an emergency, so I'd keep it as a manual switch... when something's gone wrong and you are miles away you don't want to be talking your family through booting up HA/esp32/complications to get hot water, you just want a simple labelled switch.

[Accelebrate]

I added a contactor so I could automate ours during one of the lockdowns. I was on Agile Octopus at the time and it got used a lot as I automated it to switch on whenever pricing was negative, or cheaper than gas.

Nowadays it gets triggered when there's an excess of solar and the house batteries are nearly full. Which was quite frequently in July.

As others have said, having a backup for creating hot water never hurts.

[Magic919]

I’d go down the relay route as it keeps options open. If it’s a big house the cylinder might have a pair of immersions.