How can an American HVAC technician get a job in the UK?

Hello, I'm not entirely sure if this is the right place to ask this, so please feel free to direct me to a more suitable subreddit.

My husband recently moved to the UK with me. He is an HVAC technician with qualifications in the US and 7+ years of experience. He has been calling HVAC companies and they all tell him he needs to be UK certified, but we are finding it difficult to understand how his US qualifications would translate here. He has the following:

• EPA 608 Universal Certification
• OSHA 10
• A college certificate for A/C, Heating & Refrigeration
• A high school diploma

The information we are seeing online suggests that he would need to do an apprenticeship or a course for several years which feels absurd as he is a very experienced technician, just from a different country. I understand not everything is exactly the same here as in the US but does he really need to start from 0 again?

Any and all advice would be greatly appreciated. Thank you so much!