How a Steam Vent on a Steam Radiator Works

Steam radiators were mostly used in pre-1950s homes and are still being used effectively. They are a cost-effective way of heating your home despite a few disadvantages that come with using them.

A Steam Vent is one of the most important components of a steam radiator. To understand how a steam vent works, it is important to first understand the concept behind the workings of the steam radiator itself, leading to understanding the important role of the steam vent.

How A Steam Radiator Works

The steam radiator works on the principle of a cycle based on hot water-cold water. Hot water (heated by a water heater by gas or electricity) enters a water tank and passes through the pipes in the steam radiator after reaching a certain temperature. On passing through the pipes, the water releases heat on the radiator’s fins and comes out as cold water and goes back to the water heater, completing the cycle.

Importance of the Vent

For a steam radiator to work effectively, it is imperative that the venting provided to the radiator is sufficient for good air circulation both in and out of the radiator and that the steam vent is in good working order along with its thermostat. How the steam vent works is interesting to note. It is that part of the radiator that produces the faint hissing sound heard in most homes that still use radiators.

The steam vent contains a valve that opens and closes at the appropriate steam temperature inside the radiator. It is programmed such with the thermostat to allow system air from the radiator to escape while steam is passing through the pipes in the radiator. The air at the start of the heating cycle inside the radiator is cold, hence it is allowed to escape. As the radiator gets hotter due to the steam and when the desired hot steam temperature is reached inside the radiator, the valve in the steam vent closes and prevents the steam from escaping thus keeping the inside of the radiator hot and allowing the radiator to functionally heat a house for example.

It is important to note that the hissing sound from the steam vent is heard at the start of the heating cycle when cold air is escaping the vent. The hissing sound should stop and the valve should close when the radiator gets hot. If the hissing sound continues after the radiator has heated up, it means that steam is being let out and the more steam is let out, more water will need to be heated up and used for the radiator to function.

The point to understand is that both the initial opening of the valve in the steam vent and then its closure is important for the radiator to internally heat up. If the steam vent is not functional i.e. its valve is not functional and does not open up to let out cool air at the beginning of the heat cycle, air inside the radiator will never warm up.