Yes, I would calculate that there is ~32 L of water in the system (excluding the manifold and pipes to the boiler). So on the basis of your numbers above it should be taking ~ 8 minutes to heat this amount of water. I had expected this to be the case, but as above the boiler is short cycling in...
Thanks for your reply.
No, the only connection to the boiler CH flow and return is a direct piped connection to the flow and return of the manifold. As there are no radiators on the system and the boiler claims to be able to modulate down to a suitable flow temperature the system was designed...
We are experiencing an issue with CH short cycling on a Worcester Bosch Greenstar 25i ErP boiler.
From a cold start the boiler fires for only ~25 seconds before exceeding the set CH flow temperature and entering it's 3 minute short cycle programme. As soon as the short cycle programme kicks in...