I giving 2 random runs today a try, after sometime both have ended with the message “service failure” I ain’t sure at all what happened to cause that. Services; Jubilee Class - I believe it was the 11:36 (I could be wrong for this one) a short sometime after Runcorn stop 8F - Brake Vans 10:00 - about 3-7 miles from ditton Junction Stop XSX
It's something to do with the incomplete manual firing option from what I've seen mentioned. Your fire is going out but because the firing HUD isn't implemented, there is no way to tell when you need to be shovelling coal. Go into options > HUD & Gameplay and scroll right down to the bottom where it says Steam Firing Mode, make sure this is set to automatic. Try your services again and they should work fine. I'd recommend leaving the firing mode in automatic until the manual firing update eventually comes out.
I’ll double check, but I’m sure it should already be set by me before to automatic. Edit: Just checked, it’s set at auto and would have stayed that way when I done those runs earlier.
All you have to do in manual mode is to initially open the firebox door. That should trigger the fireman to start shovelling. Don’t think you need to hit “R” as in TSC to do it yourself. The water also takes care of itself so all you really have control of are the dampers and blower.
I decided to give another run a try today to see if it was specific services only, I tried a Jubilee service with no changes made to any of my settings, at about 14:52 and had no “service failures”, so it seems to be those 2 services in particular with an issue