Ideal Classic FF250....How do you drain the system?

[ian.h]

I have a Ideal Classic FF250 fitted in the loft to replace a back boiler this was fitted in 1999.
I want to drain the system so I can replace a radiator and new TRV's.
Boiler is in the loft with cold water tank, also next to the boiler is a small red expansion vessel with gauge set a 1 bar, the grundfos pump is there as well and a small NRV at the top.
In the airing cupboard a new green Albion hot water tank was fitted, and a sunvic three port valve, the filling loop is also there and another gauge set to 1 bar I have never known it so move either up or down.
I was also toying with the idea of replaceing this boiler but it has been so reliable only one breakdown and that was the fan on the top it seized, sprayed with lubricant and been fine since, but it does sound a bit noisy I guess the bearings are on the way out.
1. Advice on how to drain and refill.
2. And should I keep/replace my boiler.

If pictures would help let me know.

Thanks in advance.

 

[jtsplumbing]

In terms of draining you should have drain points on ground floor, under radiators, is one place to look, also have a look out side could be installer fitted an external drain point, refilling is done via the filling loop in airing cupboard.

 

[ian.h]

Found the drain point it's on the radiator in hallway.
Is there any water to turn off ?

 

[jtsplumbing]

No because you have a sealed system, but look for any other drain points especially if each ground floor radiator is on separate drops, don't forget to add an inhibitor back into system when refilling

 

[ian.h]

Thank you for help, I'll replace the radiator when the weather warms up a bit in case I hit any problems