We have a PowersControl shower valve body that had a model 420
cartridge et al and the company has made a retrofit to upgrade the
entire unit to one that uses a wax element to control temperature
fluctuations, I think. Powers is now a subsidiary of Watts Water
Technologies

I have never done any plumbing in my life, except for snaking out
drains and I once replaced a copper pipe trap with a PVC one. So my
knowledge is limited, and could be dangerous.

The Lucite handle we had for the shower, that came with the shower,
wore out from the inside and it wasn't grabbing anymore, and there are
no old handles that fit those 30 year old Powers stems. So for the
time being, I took a handle from another shower that hade the same
valve controls. However, now the bathroom for the guest room and my
office, which I might start using because it takes my fiancé too long
to get dressed and put on her makeup.

On that shower we hardly ever used and now without a handle, we were
getting a little jack hammering for a second on turn on and turn off.
The plumber said that happens with showers not used. He said,
everything inside dries up. The plumber told me we needed a new
cartridge and gave me a price of $295 plus installation, if they had
it in stock and of course, if it wasn't made anymore, a new shower
valve body would be needed and that is a great deal more. So, I was
looking at least $600 if everything was available and much more if
not. Believe me, the plumber told me they don't make it anymore, I
wouldn't know the difference.

I decided that I just needed a handle and I was going to live with the
jack hammering, as it isn't a shower we used every day. Actually I
now see how that would have been a very bad idea from reading other
postings above mine. I also noted that the hammering happens more
when there is a pressure assisted toilet and we have one of those too.
So that and the fact that that shower was never used, caused the jack
hammering.

Back to the Powers valve mechanism, there are no handles for that stem
anymore so I had to put in their retrofit kit. I wrote to the Powers
people and told them about my situation. They sent me information on
the install and they gave me someone who would stay on the line and
talk me through it. Totally as a surprise to me, they also offered to
send me the retrofit kit and handle, at no charge, a $230 value. I
only expected they'd find a handle that fit the old stem.

I felt like I was in the Twilight Zone, where an American company was
that nice and that responsive. With this Power's employee John's
help, I opened the bonnet and took out everything I could. There was
one white plastic ring thing with 4 square legs and it was actually
much more substantial than a ring. That had to come out but after 30
years it wouldn't. I tried pulling it but my pliers didn't have
enough treads all the way to the top to grab the little legs. Then
John suggested trying to pry it out with a screwdriver. It just would
not go. The last resort was to chisel it out. I did and that worked
great.

So, the shower valve was empty, except for hot water seat in the back.
It took a 7/8 hex socket to unscrew it. I had one but mine was
beveled, as most of them are. The hex part of the seat was very
shallow, maybe a 1/16th of an inch and maybe it got only half way up
the bevel. Luckily John told me not to go ahead because if I stripped
the corners, I'd have a real big job for a plumber.

So, I went to Home Depot. That store is not stocked like it used to
be. I actually went to two them. They had only and 12 point but that
was also beveled. However, one of the guys in the tool department
told me that I can grind it down but that would void the warranty of
the hex socked. Like I care about the warranty and a $4 hex socket.
That was my second Home Depot and then I went to a good hardware store
and an auto supply store and neither had anything.

I went home and decided to put the bonnet back and ask John to send me
the correct socket, which he offered to do. How nice can you be?
However, putting on the bonnet didn't stop the water going into the
bath or shower and I think a piece of plastic might have gotten lodged
in the drain so the water was not even draining. I then realized I
have to try to grind that 7/8 hex socket down. I have only used the
wheel twice to cleanup screwdrivers that now look more like picks,
after I finished with them. I did the best I could. It wasn't
perfectly flat but it was enough to grab the seat and unscrew it.

So know with the very good instructions and what John told me before I
went out to look for the unbeveled socket, I was able to get the
retrofit in and working great and it is so smooth and so easy to turn.

So, Watts Water Technologies is one hell of an American Company and I
was ecstatic dealing with them. I do not work for the company or have
any relatives that do. They took a terrible situation and fixed it!

Alan