I am only getting cold water out of my Symmons Temptorl valve. I am fairly sure the problem is that the spindle is clogged up as this shower was previously not used for over 5 years.

I am going to attempt to replace the spindle and see if this solves the problem before getting a plumber to come in and give the whole valve a makeover.

My question is that when going to store I see that they carry both a Model # TA-10 for $45 and then also a Model # TA-10-RP for $40.

To the naked eye these look identical to me but then I can not figure out the price difference. Is there something I need to do to determine which I actually need for my shower? Just do not want to make a simple mistake that causes more problems.

Suggest you visit this web site. Phone number is provided for assistance. Should also inquire about warranty. Appears to warranted for life time of original purchaser.
http://www.symmons.com/Customer-Service.aspx

A quick call over to Symmons industries should prove that there is no difference between the TA-10 and the TA-10RP... as long as both are true Symmons replacement parts, they are the same thing.

Symmons will recommend that you change out the hot and cold seats at this time (requires the purchase of the seat removal tools from Symmons) and I have to say that I am in agreement in this case... new spindle with new seats will make this a long lasting repair.

Good luck!

Mark