Do I need to be in when an engineer changes the battery in my prepayment meter?

I was just wondering if I would need to be around when an engineer attends to change the battery in my prepayment meter. I have a b3 error on my meter but i am going on holiday tomorrow for over 6 weeks. The meter is located at the front of the property right by the front door with no access issues. I cant believe that the error has come up less than a day before I travel and I just dont want to leave it because it will worry me. The gas is currently off and i was just trying to top it up when i saw it.

I believe you will have to be, just in case for some reason they have to change the whole meter (which would then require the same in-house checks as for a standard replacement).

Is the b3 error stopping the meter from working correctly? I would expect that even with a low battery error, there should be a bit of life left in it yet.