Original pump (now the spare) Jabsco 31620-0092.
The PDF is named Max 3, but the pump is named Max 4!!
Jabsco website: https://www.xylem.com/en-uk/products--services/pumps-packaged-pump-systems/pumps/positive-displacement-pumps2/diaphragm/par-max-4/
The pressure switch kit is part: 37121-0010. Force 4 link: https://www.force4.co.uk/item/Jabsco/Pressure-Switch-40psi-HP/LPD
Source Relay name: TR20-2e5-1 with 15 seconds delay.
Replacement URL: https://www.ebay.co.uk/itm/267204945647
Had to swap the left and right pins for the new relay to work.
For cleaning and disinlitresg the fresh-water tank and pipework, I use ordinary household bleach containing sodium hypochlorite.
Use plain, unscented bleach without perfumes, detergents or other additives. The bleach I used contained less than approximately 2.5% sodium hypochlorite. I bought it in our supermarket at home, but also in France it was readily available.
For approximately 200 litres of water:
Add about 1 to 1.5litress of bleach to the fresh-water tank.
Mix it with the water in the tank.
Open each tap, shower and outlet one by one until you can smell a slight chlorine odour, so that the treated water has filled all the pipework.
Do not forget outlets that are used less frequently, such as the cockpit shower.
Leave the treated water in the tank and pipes for about 5 hours.
Drain the system.
Refill with clean fresh water and flush all pipes thoroughly.
Preferably repeat the clean-water flushing once more.
Do not use scented or thickened household bleach, toilet bleach, or bleach containing cleaning agents. And the tank does not need to be full. It is the pipe-network, that contains normally the bio-film.
Afterwards, keep flushing until there is no significant chlorine smell or taste before using the water for drinking.
For the future I am going to do this at the beginning of the season, and then halfway again, if necessary