JohnMarc

What I have done is simply built a plywood enclosure with plenty of ventilation ...... I painted on a resin to seal the wood completely ....... I live in an area where even plastic rusts 😂 so although everything was IP65 i wasn't going to take any chances, two years in and all good.

Yup have tried the wood burning hot tubs and as romantic as it appears and sounds I found (having recently rented one for a while) unstable as regards temperature control, not suitable for suburbia as it looked like the next pope was being elected with the amount of smoke...... or I had set up a crematorium in my backyard,,,,,,,

I am actually liking the idea of the changeover switch that turns the three phase into a single phase...... I had no idea this was possible, please elaborate.....
If I can find a way to automatically switch off the feed to the three phase geysers everything else in fact is on single phase. So a far simpler solution is possibly the 3 Phase changeover switch scenario assuming I am able to switch the instant hot water systems off. Am i right I would simply do that with a three phase contactor ..... but then what would happen when the power comes back on....is there a delay in the switchover process back to three phase. Hell I hope I have made sense here......please forgive my ignorance .....