Water pressure drop - unvented mega flo help

[Raquel91]

We noticed that we had lost water pressure around the house. On previous occasions we reset the expansion gap in the large white mega flo tank which sorted the problem. It hasn’t achieved a difference this time.
The small red pressure cylinder normally reads 1.5 maybe more Bar. It’s sitting on 1bar at mo. When opening the two black valves to increase this pressure nothing happens. We can’t hear any air and the black line gauge doesn’t move at all. Any suggestions? Thanks

 

[Dan Robinson]

We noticed that we had lost water pressure around the house. On previous occasions we reset the expansion gap in the large white mega flo tank which sorted the problem. It hasn’t achieved a difference this time.
The small red pressure cyclones normally reads 1.5 maybe more
Bar. It’s sitting on 1bar at mo. When opening the two black valves to increase this pressure nothing happens

You're telling about two totally different things there.

What is a pressure cyclone?

 

[Raquel91]

The red pressure cylinder that sits next to my main mega flo water tank. (Sorry autocorrect).

We can’t increase water pressure by either resetting the main tank air bubble by opening lowest hot water tap in house procedure etc.

Nor can we input pressure into red cylinder by the two small black valves attached to the metal braided hose.

 

[oldbuffer]

If your incoming mains water pressure is lower than the pressure in the Megaflo or the red expansion vessel (which is almost certainly for the boiler) then no water will go in.

Check mains pressure at kitchen tap. If no gauge, try stopping the flow with your thumb (messy). If you can stop it, pressure likely to be less than 1 bar, but of course depends on strength of thumb.