Firebird oil boiler hot water

[John.g]

The 35kw boiler must have sent 5.53 kwh somewhere, assuming.iit's to the store then that's sufficient to raise 125L from 25C to 65C . Are you sure the store isn't very hot? The only other route for that 5.53kwh is to the CH?

 

[Westernr1]

The 35kw boiler must have sent 5.53 kwh somewhere, assuming.iit's to the store then that's sufficient to raise 125L from 25C to 65C . Are you sure the store isn't very hot? The only other route for that 5.53kwh is to the CH?

The store feels mildly warm but not hot

 

[John.g]

Are the boiler CH flow and return pipes hot for this 10 minutes, I can't imagine the heat going anywhere else, any idea, even roughl of the heat store volume?.

 

[John.g]

Can't find a schematic of a Firebird Combi but its probably something like this Grant where the stored water is primary water, might be worth checking the non return valves and that the heating pump isn't running when HW requested. The Grant primary store is 32.5 Litres, total contents 53.5 litres.

 

[John.g]

some of these environmex have two pumps, others don't so maybe diverter valve as you suggested?.
You have two as per your photo!!

 

[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.