Which side is flow on a radiator?
Likewise, which side of a radiator is the inlet?
Standard radiators (commonly known as compact radiators) typically have side valve inlets. These are located at the bottom of the radiator too but tend to allow access from the side only (horizontally).
Just so, does it matter which side thermostat go on a radiator?
Many modern homes will have TRVs – Thermostatic Radiator Valves – attached to most of the radiators on the opposite side from the lockshield valves. A TRV should always be fitted to the inlet on the radiator and the LSV to the outlet.
With a simple central heating system, each radiator has a basic screw valve at the bottom. If you turn the screw down, you switch the radiator off: the valve closes and hot water flows straight through the bottom pipe, bypassing the upper part of the radiator altogether.