WHAT RADIATOR VALVES DO: Every radiator will have a valve on one of its pipes designed to interrupt the flow to the radiator and enable the user more ease and control when balancing the rooms. Traditionally, most valves are manually actuated; if you wanted to turn a rad off, you walk over and shut the valve down. If you wanted the radiator hotter, you open the valve back up.  A radiator valve does allow for a certain degree of control, but it isn’t an absolute. You can slow down the circulation of water inside it, but it takes a bit of time to balance a home using manual radiator valves.

Your standard radiator can be purchased bare; no bleeders, no valves, no nipples, nothing in them in their initial stage. Things change when the customer, based on their needs, selects whether they want a manual valve or a thermostatic one.  Although some of these valves represent additional costs for the consumer, they offer a versatility advantage because they can also be conveniently retro-fitted through existing hydronic systems.

WHAT THERMOSTATIC RADIATOR VALVES DO: A thermostatic rad valve (TRV) replaces a manual valve, but instead of a manual knob on the top, it has an actuator.  This actuator can control the heat to that particular radiator.  This allows for room-by-room temperature control, over and above your thermostat.  They are great in tenanted spaces, but also within a typical home.  If you keep your home at 21 degrees in the winter, but prefer your bedroom to be cooler, that can be accomplished with a TRV. If you have spaces that are generally unoccupied in your home, for example, a guest room, office, etc. these areas can be kept a lower temperature and save on heating.

What is important to understand is that when selecting a TRV over a manual valve, there is a marginal price difference, but certainly worth the investment.