Extra space in address field but no blanks in source

[DIYman]

Hi All,
This is my first post so It may be in the wrong place.
I'm using word 2013. My source data is an Excel workbook with the list filtered via mail merge. There are no empty cells in the filtered list. However my merge document creates a space between the name and the address in the AddressBlock. Can you advise how to correct this. When I used alt F9 originally there was a space showing in the code. I deleted this but the space remained.
The only matched fields in address block are First Name, Surname and address. Sample result
John Doe

Main Street

I've used mailmerge in word 2003 and did not find this problem
I don't know how to paste the "detailed or open" address block


Thanks in advance

«AddressBlock»