[andyM]

Some people have asked on here in the past how to replace the Shurflo pump pressure switch with the Maplin Standard Microswitch:
http://www.maplin.co.uk/p/low-cost-standard-microswitch-gw71n

I had to replace one today so thought I would take some photos......

Replacing Shurflo Pressure Switch with Maplin GW71N Standard Microswitch


Disconnect Power


Disconnect the 2 pump cables by pulling them away from the pressure switch spades

Undo and remove the three screws on the top of the pressure switch housing




Remove the pressure switch housing by lifting off

Be careful not to lose the spring etc.

It looks like my pump is overdue for a clean so I give the top a wipe with the cloth


The pressure switch housing is in two halves and needs to be pulled apart to access the pressure switch


You can remove the switch from the housing by levering it out with a flat screwdriver


Then fit new pressure switch by securely pressing into the housing


Next fit the two halves of the pressure switch housing back together


Then make sure the spring and seat are in correct position ready to accept the pressure switch housing


Refit the pressure switch housing into position on the pump, locate the three screws into the holes and tighten down 


Reconnect the two pump cables to the pressure switch spades


Reconnect power


Turn flow controller ON


With the pump running  the pressure switch cut off can be adjusted by using a 2mm Allen Key

[CleanClear]

Great explanation mate. I thought more people would of liked this post. However, being the Internet you're always gonna attract a critiscism...... here's my two.
[1] Seperating the switch holder, requires a fine screwdriver or similar to prise apart the two casings (to release the lugs).
[2] Once the new switch is fitted, your old spade terminals will not reconnect as they're a different size.

Your next post will be how to solder wider spade terminals on ? 

[andyM]

CleanClear is right that wider spade connectors are needed for the Maplin Micro switch when replacing the original Shurflo.
I forgot to mention that as I had previously already changed over (years ago) and so was changing a Maplin switch for another Maplin switch.
I used crimp on spade connectors, no soldering required, just cut the original spade connectors off, strip the cable back to the required length and crimp the two new spade connectors on.
Here's the link: http://www.maplin.co.uk/p/maplin-insulated-spade-terminal-female-red-jh87u

[Spruce]

Great post andyM. Thanks for sharing.

[jonboywalton75]

Fantastic Andym
Just what I needed for a job I'm doing tomorrow

[CleanClear]

Can anyone confirm.. where the spring sits in the top housing and meets up to where the allen key srew goes into, there should be a small black washer or not ? to push the spring down ? Reason i ask is i just fixed my mates and didn't want to pull mine apart and check, he changed his own pressure switch and it didn't work afterwards. On looking there was no washer or stop, made no sense to me as it would render to pressure adjustment screw useless.... hope that makes sense ?