Grant vortex pro combi 26e

[iya]

Hi...just had the low pressure switch "crumble" (3 year old boiler) and cause leaks.
Engineer unscrewed it, put a plug into the pipework, and linked the switch wires to fool the system.
Its working, but quoted £60+labour for new switch, and said "you could do the refit yourself".
I think I will but...
I didn't pay enough attention exactly what he did to reduce the system pressure to 0 prior to unscrewing the switch, but he fiddled with the "2.5bar" PRV? by liftimg and turning.

Is that right? Is this how they work?
I meant to ask him, where does the pressure (i.e. the water) go when you do this?
Do I need a cloth around the valve to absorb the water?
Whats the difference (apart from £20) between the MPCBS49 and the MPCBS62...which is the one I think I want as it has a brass elbow, and is a better,newer (?) design?

Thanks for any help

Iya

 

[oilboffin]

The new ones have a male female elbow and a brass part if the boilers inside you use all the parts if it's outside you screw the brass bit in and put the switch onto that but the new ones don't have a switch so what I do is screw a manual air bleed in the pipe and leave the electrics linked out.Bob

 

[oilboffin]

The water goes on the floor through a blow off pipe you don't need a cloth.Bob