Sticking shower thermostatic control

[opps]

Hi all

The following thermostatic valve keeps sticking, it should rotate through about 350 degrees but it can normally only be turned about 160 degrees. I took the crown off and sprayed some WD40 on to the end of the spindle and it was fine but only for a week or so. I also noticed that it clicks at what is possibly the middle temperature.

Additionally water leaks out of the end of the flow spindle when the valve is open.

Do they both need replacing or can either of them be repaired? IIRC the thermostatic valve was only replaced about 3 years ago.

Thanks in advance.

 

[MeldrewsMate]

In your pics, I read it that the bottom shaft sticks and the top shaft leaks. Is that right?
BTW WD40 is evil stuff, it washes away lubricant and swells 'o' rings and seals. Get some silicon grease or spray for rubber type materials.

I can't help you with a name, but it looks typical of many unbranded Trevi copies, of which there are plenty, so should be common on sites like Ebay.

 

[opps]

Thanks MeldrewsMate.

Yes, the bottom sticks and the top leaks.

Is the top leaking because of a failed o-ring? Do I just need to remove the circlip and pull the innards out to get to the o-ring (after first removing the valve)?

And do you also think that the thermo valve definitely needs replacing or might some silicone grease suffice? And if I remove either valve, do I need to use PTFE when putting them back or do they have gaskets at the end?

 

[Madrab]

Both valves have circlips which indicates that they both have O-rings. The top control valve will have worn O-rings, hence the leak. If you can find the correct size of O-ring then it can be replaced but if it's not a bod standard size then it might not be easy to find the exact size.

The bottom thermostatic valve will be harder to repair and all depends on whether the valve can be stripped down or not. If it can and you can remember how it all fits back together again then some silicone grease may certainly help. If it's excessively worn though then no amount of grease will sort it and it would need replaced. Depends on whether you want to try and strip it and if you will actually know what to look for to identify if it is excessively worn or not.

 

[polesapart]

showerdoc.com is very helpful for spares, identification etc.