Firebird oil boiler hot water

[SimonG]

Two pumps = no diverter.

Need to know if rads are getting hot when hot waters ran. If so it's a non return valve.

 

[exedon2]

I'm attaching a firebird technical update I got some years ago when we were repairing one ,
Seem to indicate heat store should be 78 C also describes how to test thermistors

 

[John.g]

They claim 120L available at 20LPM at a 40C dT from the 40L primary store (78C) presumably as the boiler will be firing at 35kw output as well.
Any idea of the continuous flowrate at say 40C once the store has fallen to say 50C?, there will obviously be a dT between the PHE and the DHW temperature, is say 16.0/16.5LPM at 40C achievable at a mains/DHW dT of 30C.