shower cuts off when water starts getting hot

cirrus114 · 02-10-2013, 03:59 PM

Hi, I have an issue with my shower. I installed a single handle mix valve when I finished my basement about 7 years ago, I do not remember the brand I used. Recently, the shower will shut off (with some water dripping from the shower head) when the water starts getting hot. I have replaced the mixing cartridge and the pressure balance disk, and the problem remains. There are what appears to be adjusting screws in the brass mixer at the hot and cold water inlets. Should I try adjusting these? Help please...

percygreen · 02-10-2013, 04:20 PM

Those screws are more than likely just shutoff valves. You could adjust the flow a little bit with them, but for the most part, all that is going to do is affect the pressure.

Unfortunately, that's about all I can tell you about this problem.

cirrus114 · 02-10-2013, 04:26 PM

Thanks Percygreen, this one has me stumped. I finished the basement myself some time ago, did the plumbing, wiring, framing, sheetrock - everything. so I am pretty good at this kind of thing, but I am totally stumped. I hope I do not have to replace the brass mixer, but at this point I don't have a clue what else I can do

747 · 02-10-2013, 04:35 PM

deleated

percygreen · 02-10-2013, 04:39 PM

How did you change the cartridge without knowing the brand?

Hopefully it doesn't come to this, but if you do have to replace the whole thing, I'd recommend going with a big brand like Moen, Delta, Kohler, etc. That way if you do have problems in the future, it will be easy to get parts. And KEEP THE PAPERWORK that comes in the box! There is usually an exploded view of the faucet that can be valuable in not only identifying which part is the problem, but what the part number is, which will make your life much easier.

**oh'mike** · 02-10-2013, 05:19 PM

Check those brass screws---you have a pressure balancing cartridge,I believe---those are shut off valves---if they are not fully open---the perssure is out of balance and your good cartridge will shut down----open those shut offs and then get back to us.

cirrus114 · 02-10-2013, 05:44 PM

Percygreen - I took the old parts in and matched them up. Model was a "Tuscany 50524" but everything I can find tells me the "tuscany" is a style not a brand. I will check the screws - maybe open them up. but since I really do not understand them - I am not sure the results. this thing has worked great for close to 7 years. Do these screws have spring loaded pressure valves with them?

joeplumber85 · 02-10-2013, 06:10 PM

Chances are you have an obstruction somewhere on either the hot or cold side coming into the shower. When not in use the pressure will build up to normal and the shower will function fine initially, but after a few seconds the obstruction will reduce the incoming flow to a point where the pressure balancing unit will kill the shower.

An obstruction could be dirt, sand, or a partially closed valve such as the integral shut-offs on the cartridge. If it was me, I'd make sure they are open all the way, and if that's not the case then close them both, remove the cartridge, and then check the incoming flow on both sides.

cirrus114 · 02-23-2013, 04:40 PM

Thanks guys for your replies. Here is what I found. Those two shut off screws have small spring loaded plunger valves in them, and one was stuck shut. Took it apart, cleaned it up and put it back together - all is working great now.