ideal ff240 boiler pressure readings

[Camilla]

We just moved to a house with very old boiler ideal ff240, next to the boiler there is a red cylinder , I assuming it shows boiler pressure. Not sure how to read it as there are 2 needles , red and black. Could anyone help please, is this right pressure? The heating and hot water works but the water from hot taps has very low pressure.

 

[steadyon]

1. The pressure (probably flow) from the taps has nothing to do with the pressure in the boiler. It is a function of the mains pressure for mains connected outlets and the vertical distance from the bottom of the cold water storage cistern (usually in the loft) to the outlet for tank (hot or cold) fed outlets.
2. I would guess that your boiler is connected to a sealed central heating system, hence the red expansion vessel and the pressure gauge.
3. There are red and black pointers for the pressure gauge:
3a. The red pointer is normally adjustable by hand from outside the gauge, and is used to indicate the normal pressure.
3b. The black pointer responds to the pressure of water in the system, and should show the same pressure value (in bar) as the red pointer.
4. Normal pressure is around 1.3 bar. Your gauge appears to indicate (red pointer) a norm of around 1.15 bar. The actual pressure would appear to be little more than zero and needs to be increased to, I would suggest 1.2 bar.
5. Somewhere on the system will be a metal braided hose. This should have a valve at each end (although may have only one), each valve having either a screwdriver slot or a small plastic lever. The valve would normally have the slot / handle at right angles to the pipe.
6. To re-pressurise the boiler:
6a. Turn the boiler off an let the system go cold.
6b. Open one valve by turning its slot / handle to be parallel with the valve. This opens the valve to let water pass.
6c Open the other (or only) valve as above, slowly. You should hear water go into the system and see the pressure on the gauge rise as indicated by the black pointer.
6d. When both pointers are in line (at 1.2 bar), close the second operated valve, then close the other valve (if any). The boiler has been re-pressurised.
6e. One or other of the valves may have a small hexagonal bolt head on it. Don't under any circumstances fiddle with this, or you may get very wet.