When I did my research in selecting shower fixtures I couldn't tell the difference between pressure balance and thermostatic valve and after much reading I came to this conclusion. I'm only talking about the Pfister line since that's what I purchased. Pressure balance valves Normally work at a maximum of 2.5 gallons per minute which is what a standard shower head needs. They normally operate at full pressure when turned on and the single handle valves only adjust the temperature, not the volume, unless you purchase a higher end fixture. The temperature is controlled by way of adjusting the water pressure and attempts to maintain it with within +- 3-5 degrees and you will notice a drop in water pressure when a toilet if flushed etc., since it's attempting to balance the pressure to maintain temperature. There will not be a temperature setting on the trim kit as since the pressure balance valve has no idea what temperature the water is, it only knows where you adjusted the handle. Summer and winter the temperature to the valve will be different so you adjust accordingly. Based on the 2.5 gpm flow rate you can normally operate one item at a time unless you don't mind a reduction in water pressure. Thermostatic Valve; Pfister has a 7.0 gpm and a 12 gpm flow rate at 70 psi, to accommodate multiple shower heads, rain cans body spray to operate at once. They generally come with at least one volume control and you can add onto it as well as add diverter valves. The temperature is monitored by way of a wax ring and when it senses a change in temperature, not water pressure it adjusts up to 1-3 degrees without changing the pressure. Regardless of the water temperature coming into the valve, you adjust the temperature on the indicated ring and it remains that way any time of year. In other words, it has a temperature setting on the trim kit. Since shower heads are normally 2.5 gpm, body sprays 1.6 gpm, you can add up what you want to operate at one time as long as you don't go over the either 7.0 or 12.0 gpm. Again this is based on the Pfister pressure balance custom line.

https://www.heatingair.org/ How to Identify your type of thermostat? The most simple way is to observe your home heating system and then look at the backside of your thermostat. If your home heating/air conditioning system is central (a central furnace or boiler) and you have many ducts or pipes going through all rooms (starting from the furnace/boiler) you should be having low voltage thermostat in your home.Now when you look at the backside of your thermostat, if you see 6 or more wires (thin, multi colored) in its back (going into a board) you can confirm you have a low voltage thermostat. A line voltage thermostat is used only with single stage heating systems (like forced fan heaters or baseboard heaters) and their will be only either 2 wires or 4 wires coming out of its back. These wires will be thick (as they carry higher current & voltage) and often will be in a combination of Black & Red or Black & White color. Well, this is the most important classification when it comes to types of thermostats. In fact, there are only two types of thermostats – either low voltage or line voltage. The other classification (based on features) which brings in Smart Thermostats, Programmable, Non Programmable etc. applies to both line voltage and low voltage thermostats. Smart Thermostats are available for both low voltage & line voltage categories. Similarly, programmable & non programmable thermostats are also available in both categories. So lets see which all are the best models available for both categories and how they differ.

I found quality bath through gardenweb, where lots of people have said wonderful things about them. A friend bought a faucet from them recently and was very happy. I've not purchased from them yet, but have found that they have consistently excellent prices on Hansgrohe. I just offered that suggestion because there are so many websites selling bath and kitchen stuff under the "bait and switch" model; I hate when I finally decide to order something, send in my credit card info, and then get a message that they don't have THAT item, but could easily sell me something different. Quality Bath seems to also have a brick and mortar operation, and they get good reports so I would feel comfortable recommending them.

I am thinking that you simply are reacting negatively to the newly implemented 2.5 gpm restriction. As you point out in your other thread, going from 8 gpm to what you have now is a huge adjustment. Will your plumber (or contractor) tell you if 3/4" pipe was ripped out? Or was it also 1/2"? You are right that either are in the code, but does the valve and shower head combo prevent any difference in what gets to you in the shower, anyhow? Does your apartment building now require 1/2" and that is why you got it? However, if the supply valve is supplying a satisfying pressure at a "warm" setting, where both hot and cold are mixed, I understand your question about why you can't get the same pressure and volume of water when you turn to only hot water. Barnes Custom Builder does not address that in their first answer. It sounds like you are willing to replace your valve if that will get you the shower you want, you just want someone with more understanding of the way these valves work to give you word that it will be worth it. I can understand your reasoning about the valve you have, because the handle controls both volume and temperature, you should have max volume at the highest temperature, yet you are getting less pressure with just hot water being called to the shower. What is going on? Does pressure coming from the hot water tank naturally differ from the pressure of the cold water delivered directly from the city? These are all questions that a plumbing professional with an understanding of the dynamics of this type of apartment building situation needs to address with you.