I’m a spark and being so for over 40 years and never seen a 2 pole Henley block be responsible for burning a house down, providing terminals are tightened to the correct specifications and torque, which still applies to single pole blocks.
16mm tails are standard for heatpump & charger installs. Heatpumps also use Type B or F RCD/RCBO, where as Chargers typically use Type A and are fitted to the non RCD side of a consumer unit, as you see in split or individual CU’s however, if you agreed to pay for a larger split CU and 25mm tails, theres no reason why they couldn’t do it
As explained, you need a Type A RCD/RCBO, that has 6mA DC protection for an EV charger. A Type B RCD/RCBO is Type AC and doesn’t have DC protection. In the highly unlikey event, you can find a single pole Type A RCBO for your F&G CU, you would still require at least 2 spare ways to fit an SPD (surge protection). That said, you’ll find the installer would disagree with what customer service have told you via email, as they don’t have a clue, and would in 99.9% of cases prefere the seperate CU route, which frankly, it keeps it seperate to your house CU and would be my prefered route of install. You could replace the heatpump CU to a split board, but it won’t come cheap through Ohme!
Arranging through Ohme for any upgrade work that isn’t needed for the charger, would be by far way more expensive than getting a couple of quotes and getting a local spark to carry out the work.
