The height grid to convert between WGS84 and RH2000 can be found at 'https://www.lantmateriet.se/contentassets/493a548ae6c14631968c401dc08086c5/swen17_rh2000_txt.zip'
Unzip the .txt file into your FME installation, to \\Reproject\\GridData\\Sweden, and rename to .grd.
FME can't read the grid file directly, but needs a catalog file. In the folder FME\\Reproject\\GeoidHeightGrids\\World create a new text file and rename it to WGS84-RH2000.gdc. Edit the file in Notepad and add the following line:
..\\..\\GridData\\Sweden\\SWEN08_RH2000.grd
In the CsmapReprojector, choose the catalog file WGS84-RH2000.gdc for your height grid.
Hej!
I am trying to convert .las data from elipsoidal to orthometric heights using SWEN17-RH2000 geoid height grid following the same logic provided by @DaveAtSafe, however an error which is linked to a failure of opening the .grd file pops out:

I could not find SWEN08-RH2000.grd file to compare if the format hasn't changed, yet I doubt it would be an issue. Any ideas and suggestions of solving the transformation are welcome.
Thank you in advance,
Vadis
Hi @wandenis!
I have the same problem, did you find any solution? Or maybe @DaveAtSafe can help?
Thanks!
/Magda
Hi @wandenis!
I have the same problem, did you find any solution? Or maybe @DaveAtSafe can help?
Thanks!
/Magda
Hi @lazermagda,
The file seems to have been moved. I have updated the location in the answer.
Hej!
I am trying to convert .las data from elipsoidal to orthometric heights using SWEN17-RH2000 geoid height grid following the same logic provided by @DaveAtSafe, however an error which is linked to a failure of opening the .grd file pops out:

I could not find SWEN08-RH2000.grd file to compare if the format hasn't changed, yet I doubt it would be an issue. Any ideas and suggestions of solving the transformation are welcome.
Thank you in advance,
Vadis
Hi,
I am having the same issue. Did you solve the problem?
Hi @lazermagda, @wandenis, @hhammarstrand,
The .grd file supplied is the not the same format as the .grd files used by FME. Please use SWEN17_RH2000.txt instead, then change the extension to .grd.
Hi @lazermagda, @wandenis, @hhammarstrand,
The .grd file supplied is the not the same format as the .grd files used by FME. Please use SWEN17_RH2000.txt instead, then change the extension to .grd.
I did try that and that did not work, even after several restarts of FME. However, I solved it when i restarted FME as an administrator.