BoilerMate 2000 Boiler overheat stat

[Roblongshanks]

Hi all hope someone can help me with this question about the lovely boilermate 2000.

Does anyone who has experience with the boilermate 2000 know if the overheat stat on the boiler kicks in
does that auto trigger the radiator pump to fire up in order to cool everything down?

Reason for the question is I came home last night to find all the radiators were lukewarm even tho nothing was calling for heat and the boiler had gone into F5 lock out (glow worm). I haven't managed to reset the overheat stat yet as Sod's law I left all my tools on site.
I've not had much experience with thermal store systems so could do with a little help so I know what to expect when I get home. But that leads me to my next question of does anyone have an idea what might have caused the boiler to go into F5 lock out? PCB on the boilermate seems to be ok, HW pump is working fine, CH pump is constantly on unless I turn it to immersion HW (is this because of the overheat stat?) and obviously don't know about the boiler pump as haven't been able to reset the stat yet.

Hope you can make sense if this and any help would be appreciated.
Thanks

 

[Agile]

I did not know that it did run the pump but it would be logical for it to do so.

Has the immersions been checked for their temperature settings?