If you ever lived or still live in a traditionally-designed house with substandard plumbing, you are well aware of why pressure-balance shower valves are so popular today. Chances are you have had your shower, more than once, disrupted by a sudden blast of hot or cold water. This scenario often results from a disruption in the water cycle, maybe due to starting the washing machine, toilet flushing, or using the dishwasher.
The shower faucet fails due to a sudden drop in hot or cold water, often due to the opening of another water fixture, reducing that available to the shower. To address this problem, one can re-do the plumbing work with larger pipes so that fluctuations in water demand won’t be noticeable. However, this option is quite expensive, and that is why an alternative shower valve is sought, one which will compensate for the water pressure changes.
Shower faucet set manufacturers got you covered with their pressure-balanced shower and Thermostatic shower valves. Although not a requirement by building codes, these valves come in handy. So, which will work best? All factors kept constant; it depends on budget and preference.
How Do These Shower Valves Work?
The Pressure-Balance Valve
The pressure-balance valve is a single-mixing valve that operates by sensing the hot/cold water ratio to deliver the required water temperature continually. The single handle valve controls both temperature and volume interchangeably with an extra spool, pressure-sensitive piston, or diaphragm.
In case the incoming water supply (either cold or hot) has a drop in pressure, it adjusts the opposite water outflow for it to match. This function maintains a stable water temperature that comes from the rainfall showerhead.
One drawback of this valve is the sudden pressure changes in water might reduce the outflow on the showerhead, but the temperature will remain the same. Another disadvantage of this valve is that the debris and scale in water, such as rust, can cause sticking of the pressure valve.
The Thermostatic Valve
The Thermostatic shower valve regulates the water temperature similarly to the car radiator thermostat. Unlike the pressure-valve, which features a pressure-sensitive piston, the thermostatic valve is made of a temperature-sensitive element, which contracts and expands according to the fluctuating water temperature.
If the water temperature goes above that required, this temperature-sensitive element expands, allowing more cold water to maintain the temperature setting. The water heater can be set at a different temperature from the shower valve; hence you can achieve higher water temperatures in other faucets such as dishwashers, washing machines, and more.
This valve type maintains a fixed temperature setting, whether the water is running full blast or trickling. The showerhead handle independently sets the flow rate and water temperature. The set temperature remains constant until it is reset. If the flow rate is supposedly reduced due to an open faucet, you compensate by increasing the flow rate. These valves are ranked more superior than the pressure-balanced valves but are more capital intensive.
Which Overrides the Other; Thermostatic or Pressure Balance Valve?
For those who want a budget-friendly option, a pressure-balance shower valve should serve in their best interests. This shower faucet set goes for around $80-$300, far less than the thermostatic valve, which starts at about $250, but you won't lack cheaper alternatives if you shop around.
Although it is an expensive option, the Thermostatic valve is more superior. Some of the three significant upsides of this valve are:
Easy to use
Adjusting the temperature is quite easy and remains that way until you reset it. Also, it prevents scalding and thermal shock that comes as a result of fluctuating water volumes.
Works Well With Large Showers
A single thermostatic valve will service a shower having more than one shower head. You can use the shower overhead and handheld one simultaneously when maintaining a fixed temperature.
The water volume and temperature setting are independent. You can use the shower at a lower flow rate and still achieve the required hot water temperature. Also, the setting is automatic; hence you do not have to fiddle with it to achieve the perfect temperature.
To sum up, the repair and installation process for the thermostatic valve and pressure valve is similar. The plumbing costs will be the same since there is no extra work needed. Nevertheless, you should hire a plumber if you are not certain enough about your plumbing skills.