Replacing an obsolete(?) single-hole kitchen tap in a granite worktop - any pitfalls?

[Careful_Bodger]

My kitchen tap is over 12 years old. The internal sealing surface seem to be failing. I have changed the ceramic 1/4-turn valves several times, but after a few months a slow drip returns, i.e. from the tap nozzle.

If a complete tap replacement is advisable, what are the DIY pitfalls? The current model is a Carron Phoenix Savona - the fully curved type with a brushed-effect finish.

This exact model appears to be no longer available, so I guess they ceased manufacture? Did anyone take on this design?? Ebay seems to have an L-shaped variant, but the brushed-effect finish seems less common.

Please comment if this type has any quirks that makes de-installing and replacement more difficult, including identifying a mechanically compatible replacement - which is something I'd like to do even if using a professional to do the replacement fitting.

As far as I can ascertain, most mounting through holes are a standard 35mm, but please shout if you know different. I have the original fitting Instructions, which do not have this detail. What is the risk of another model *not* fitting the existing through hole in the granite.

What are the best tool options to attack the mechanical fixing? I may need a swivel or UJ.
There is access from below, but the back panel might foul a direct attack (see side panel cut-out in the photo).
Is that long nut a single, or likely to be part of a locking nut pair? I think that's a photo image artefact suggesting the latter.

The wet attachments look fairly straight-forward, but any advice welcome to ease the way.
Anything to penetrate the scale/goo?
I would need to remove the drainage assembly for better access.

TIA

 

[flameport]

What is the risk of another model *not* fitting the existing through hole in the granite.

Basically none. Kitchen taps generally fit into the same sized hole.
Don't buy taps on ebay. Plenty of decent places to buy taps from.

Is that long nut a single, or likely to be part of a locking nut pair? I think that's a photo image artefact suggesting the latter.

It's a long threaded rod which goes into the body of the tap. The brass nut is there to tighten against the metal ring which holds it against the worktop.
Either unscrew the brass nut or put a flat screwdriver into the slot at the end of the rod and undo that.
There are tools for such things: https://www.toolstation.com/minotaur-box-spanner/p96418

Anything to penetrate the scale/goo?

If they don't unscrew, just press down on the plastic collar where the copper pipe goes into the plastic fitting and pull the pipe out.
Likely to need some new fittings for connecting the new tap anyway, depends on what it's supplied with.

 

[Careful_Bodger]

Ooo - thanks for pointing out the slot in that threaded section. I missed that, but it's defo there!