Grohe basin mixer tap cover not coming off

[Odd Lion]

I have a Grohe "Eurosmart Cosmopolitan" mixer tap which doesn't turn fully to the right (cold). I fear some sloppy installation and/or an (unwanted) hot water limiter incorrectly installed. Anyway, the guy who installed it is long gone so I'm on my own DIY now.

I took the grub screw out no problem, but for some reason the handle isn't coming off like it does in the Grohe instruction video. Is it possible that limescale has caked it on to the point that 5 minutes of prying and pulling will not budge it, or am I missing something? (in fact it's 5 years old, as I haven't been living in the house, so limescale is definitely a possibility).

So two issues
1) How to get the cap/handle off? I've tried brute force but no chemicals, really don't want to damage the cartridge.
2) What might be causing the limited swivel to the right (20-degrees instead of the approx 50 degree swivel to the left)? Could the hot water limiter have been installed backwards so it acts like a COLD water limiter?

Thanks in advance for any help or advice

 

[king of pipes]

Any pictures ? Always easier to advise

 

[Odd Lion]

Any pictures ? Always easier to advise

It looks like this (as far as it turns to the right). I had thought removing the grub screw was the standard removal method, but it really won't budge.

 

[king of pipes]

I would of thought the same to be honest if it's not removable then get it changed is my advice . Kop

 

[Odd Lion]

I would of thought the same to be honest if it's not removable then get it changed is my advice . Kop

Thanks KOP. It has a grub screw, and Grohe even has a nice video showing how to take it off, so it is definitely possible. From your experience, could limescale cause this kind of problem, or anything else?
Thanks in advance,
OL

 

[Stigster]

Tap heads can get ridiculously stuck with limescale and corrosion. You could try squirting a penetrating oil with straw attachment through the grub screw hole and leave it overnight to see if that helps you free it.

Ultimately, Kop is probably right and it may be better in the long run to replace the whole tap, especially if the oil doesn't work.

 

[king of pipes]

Anything is worth a try mate kilrock is a good product available in a spray and will not damage anything spray some in where the grub screw came out and leave over night a few taps to loosen it may just work ? Regards kop

 

[steadyon]

I'd be a bit careful using Kilrock unless you are absolutely certain the handle is made of brass. I've found that Kilrock (which I think is an excellent scale remover) appears to dissolve zinc die-castings.

Given the tap is Grohe, it is most likely brass. I can't think of a non-destructive test to make sure, other than letting it go cold, then holding it in the hand. If it still feels cold after 10 seconds or so its probably brass, if it starts to feel a bit warm, it could well be die-cast.