Solar PV Hints, Tips & Troubleshooting

Hi All,

I have a quick question on hot water diverters and the immersions ye have. I don't have PV yet, still in the research phase so expect a large post in the near future.

From what I have read on Boards so far, it sounds like people have a standard HW cylinder with the immersion installed. I'm wondering if anyone has a willis heater as seen in the image below, and how do they find it.}

A brief description for those who arent familiar. The willis heater is a small unit (think thermos flask size) that is installed externally to the cylinder. It has a standard 2-3Kw element installed, but does not need to run as long as an standard immersion to provide HW. As this is a large element for such a small volume of water, it heats up rapidly. The natural convection of hot water means that it will exit the top of the willis heater and begin displacing colder water at the top of the tank while drawing the coldest water from the bottom of the tank.

When I first installed one, the cylinder had to be drained thus my initial test was performed with a tank of stone cold water. I pressed the timer button for 15minutes and tidied up after the works. when the timer elapsed, I ran all the hot water I had into the bath to see, and managed to get 2 inches of boiling water before it started to cool(but was still hot)

I don't mean ti hijack a thread, but was just wondering if people have this installed with PV and does it work out better or worse.

P.s. for anyone looking at getting this (PV or not), it might not work well if you have a secondary return fitted (depending on plumbing)

Sounds like the BMS in the battery pack is actively changing values.

You need to look at the values when the battery is fuller.

And I would suggest that you set a schedule to stop it discharging between 23:00 and 08:00 if you are on a day / night tariff.

You think it would be slower ?

If so, I still have the other internal immersion in situ, so could dedicate that to a diverter if needed.

On another note, is the 2020quotes thread the best place for research for a DIY install ?

I'd hate to start another thread asking similar questions, but will finish that thread and this one first.

this is the only screen where I see timers, so which one of these would be to stop it discharging during night rate hours? (I have a day/night meter)

The Discharge Limitation is 8 amps, and no matter what I set it to, as soon as I save it and go straight back in, it defaults back to 8 amps!!!

You need to go to Battery select and click into the what ever battery is set and then it shows up if I remember.

The menus aren't the greatest.

Try this, select another battery from the list, save then go back in and select the correct battery, maybe it will reapply the correct settings.

I'll have a look in the battery select menu,

buy on the discharge limitation, no matter what I set it to it always defaults back to 8 amps!!

I'll try again and set it to 100amps and see if it sticks!

I’ve changed the discharge timer to 8am - 11pm, and also set it to ‘Run’

is this correct?

I noticed that 100% of solar generation was going straight to the battery, and the house is running off the grid…. Would this be the system simply forcing all solar into the battery 1st to get it back to 10% SoC?

I you do not night charge then set it to stop and set to 00

Looks like I’m sorted…

checked and battery was at 24%, Solar was running the house and excess going to the battery.

came down and boiled the kettle, and MyEnergi app showed the house using 3kW (all from Solar + Battery, and none from grid)…. (Solar currently generating about 1kW)

Happy days and many thanks for all the help and support.

I agree - but Andy and I had the SAME installer :) :) i think its PBKAC