Pump Pressure adjustment

[Norman_E]

The photo shows a Propump FL35 pump which I have bought as a cheap spare for the boat. With the cover over the pressure switch terminals removed there is a Philips headed screw visible between the terminals. Does anybody know if this screw adjusts the pressure? It is not screwed fully in, and can be turned easily. The pump is set at 35 psi and if I have to use it to replace the domestic water pressure pump I need to drop the pressure to about 30 psi because of the calorifier.
EDIT I think this pump may be a similar design to a Jabsco Par Max 4

 

[charles_reed]

The Phillips screw holds on the pressure sensor valve, a separate item which is easy-to-replace, unlike earlier pumps.
The whole sensor unit has to be replaced, as I understand, as it's pre-set and non-adjustable.

 

[ccscott49]

The Phillips screw holds on the pressure sensor valve, a separate item which is easy-to-replace, unlike earlier pumps.
The whole sensor unit has to be replaced, as I understand, as it's pre-set and non-adjustable.

Actually, the sensor is held on wiith the two small philips screws in the sides, the one in the middle is a pressure adjusting screw. The sensors are notoriously unreliable.

 

[[2574]]

I have just fitted a Par Max 4 and yes the central screw can be adjusted to change the pressure cut out. I've the 15/25psi version but apparently its no different to the 30/40psi version except the screw is tightened a little. I was advised by Jabsco that I could make the adjustment and needed to to make our shower heads operate correctly.

 

[Norman_E]

Thank you all. If I have to use it to replace the main water pump I will experiment with the adjustment. It is however just a general spare and could easily end up draining a shower or pumping out grey water, where its pressure setting would not matter.