View Full Version : anti scald
09-09-2005, 04:19 PM
I am renovating my bathroom... I want to have a pair of simple shower valves, one hot, one cold. This means I need a remote pressure balance unit or a thermostatic device installed in the crawlspace beneath the shower. I believe these two systems approach the problem of scalding somewhat differently. My question is -- which of the two is a better idea? I haven't researched this enough, but maybe they come with dual capabilities? If so, is that overkill? Could you guys enlighten me, please? Thanks!
09-09-2005, 04:48 PM
As I understand it, a temperature controlled valve also functions as a pressure balanced one, but a pressure balanced one does not function as a temperature controlled one in that if your flow remains the same and your incoming hot water cools off, it won't adjust, only if one side or ther other's pressure changes.
I've got a temperature controlled valve in my shower, and it is nice to basically set it once, then just turn on the flow to the volume you want each day. Once the hot water arrives from the heater, the valve keeps the shower output temperature constant. When, not if, it eventually fails (hopefully a long time), a temperature controlled valve will probably cost more to fix; by how much, I can't tell you.
09-09-2005, 07:49 PM
Thank you for the response. A question -- does a thermostatic valve prohibit you from taking a warmer shower one day, a colder shower another day... that is without going to the trouble of re-adjusting the thermostatic valve settings? In other words, does it in some way override one's freedom to adjust temperature by simply adjusting hot/cold valves?
09-09-2005, 08:09 PM
No. The only thing that changes the settings on a pressure balanced valve is 50 pounds one day.....110 pounds the next. That is unlikely in many cases. The adjustment behind the handle as mentioned rarely has to be changed.
09-10-2005, 12:55 PM
Most thermostatic valves have two controls - volume and temperature. Each can be easily set individually. It's just that once you find a good temperature, you may never have to change it again. If multiple people have their preferences, just not where it is, and readjust to your preference when you get in there. And, as you use up all of the hot water in the tank, it adjusts for you as best it can, until it eventually just runs the water from the hot line.
The pressure balanced units just maintain an equal pressure between the two sides so that if a toilet or faucet is used on the cold water side, the hot water pressure will be reduced to maintain the temperature balance you have set. There are no settings on it. A thermostatic valve will try to maintain the temperature it is set at, and has to be accessible if you have multiple temperature preferences. I am not sure why you would want the individual controls, when there are many better ways to do what you wish to.
09-11-2005, 12:39 AM
My decision making process is invariably a long and tortured route, so I may well evolve beyond my current fixation on separate hot/cold handles. I guess the sizeable eschuteon for the single handled, thermostatic control included units just doesn't appeal to me aesthetically. When I found out that I could install a remote unit of one type or another, I figured I could construct a system that would be safe and would still appeal to my sense of aesthetics. It sounds as though a remote pressure balance unit would be what I'd chose because a thermostatic device could require re-adjustment depending on how hot or cold people would want the water. But your words to the effect that I could configure a better system if I went about it in other ways haunt me. Aside from aesthetic concerns (which are probably somewhat ridiculous to everyone else but me), am I on the road to configuring a technically inferior system if I place a remote pressure balance unit underneath the shower? If my plan puts people at greater risk of being scalded, I'll scrap it. Thanks for bearing with me here.
The remote units, at least all that I have seen have very small ports in them which will limit the flow through them. In addition, they have to be in an accessible location for occassional servicing. Have you checked the Price Pfister "2 handle" pressure balanced unit? It does not have separate handles for hot and cold, but one handle controls the temperature and the other the volume, (once the temperatur control is turned on).