Pressure balance vs Thermostatic shower valves

[Adam G]

I recently installed a pressure balance valve with a single handle in my new shower to replace an old dual handle system. The dual handle system had incredible pressure on both the hot and cold.

When the single handle is at the midpoint the pressure is great. I assume this is because it is mixing the maximum amount of hot can cold water 50/50.

However, I like to take very hot showers. When I move it beyond the midpoint the pressure drops. Not a lot, but enough to notice and wish it was back at max pressure. Maybe 10-20% less. I played with the anti-scald setting and didn't see much improvement.

Would switching to a Thermostatic valve fix this problem, so that even on the hotter settings I would get the max pressure available? Or should the pressure balance valve when on the hotter setting still maintain the same pressure it had at the midpoint?

 

[Terry]

It's pretty common for balanced valves to drop a bit of pressure when switching to full hot. New code (not really that new) limits shower heads to 2.0 gallons per minute. Old heads would easily do five. What I have noticed is very small porting up to the shower in the valves now. If you had a two handle before, it was a straight shot to the shower head with guns blasting.
One method during installation, something we never really think about on showers, is to use the tub port for the shower head. There is more volume from the tub side of the valve.

 

[Sponsor]

 

[hj]

quote; something we never really think about on showers,

I ALWAYS "think about it' for a shower, if the valve body can be inverted. I would not bother with it for something like a Moen valve that would have to be piped around the valve body.

 

[Sylvan]

The flow restrictors in a shower head can cause scalding when there is a drop in water pressure

So I usually show accounts how to remove the restrictor and if NO Children or elderly are involved I will set the Delta to a little over 120 DEG

 

[Jadnashua]

If a pressure balance valve is working properly, you will not get scalded by a pressure drop regardless of restrictions. That's their entire purpose in life.

FWIW, Delta's documentation on their pressure balance and thermostatically controlled valves indicate that, at least with their designs, a thermostatically controlled valve will be able to flow a higher volume than the pressure balanced one.