I have a Symmons Temptrol Model A shower valve that suddenly if I flush the toilet the water
Gets scalding hot. Any suggestions the unit is approx 3/1/2 years old and it has always worked previously. Thanks in advance.

I assume it is Single Handle shower faucet: there is an anti-scold device inside your faucet that is malfunctioning. That device is there to prevent what you are describing. You will have to close water for the whole house, remove the shower faucet cartridge and either clean it or replace it with new one.

Hi all...

The Symmons temptrol tub or tub/shower valve only has a set screw to limit the temperature. This simply limits the rotation of the handle... nothing else.

My guess, just like Milo's, is that the cartridge has gone bad and needs to be replaced. It is an easy fix. Shut water off to the valve, remove the trim plate, and back the large nut out and the stem unit should follow.

This is tricky, however, as I have been installing the symmons shower valve my entire life and have never heard of this complaint... until now... ;)

Let us know what you think here Merled.

MARK

I will get a new cartridge and see what happens.
Thanks everyone.
Merled

Hi Guys you are great I am waching the threads here from Hong Kong and read all your good advices, Thanks.

Regards,
John