Massachusetts Oil Burner License Practice Test

What can be the effect of a plugged siphon loop on a steam system?

1. Excessive heating in the system

2. Insufficient heat in the living space

3. Reduced water level in the boiler

4. Unstable pressure in the system

The correct answer is: Insufficient heat in the living space

In a steam system, a plugged siphon loop can lead to insufficient heat in the living space. The siphon loop is designed to trap condensed steam and allow it to return to the boiler for re-heating. When this loop is obstructed, the return of condensate is inhibited, which disrupts the flow of steam through the pipes. As a result, there may not be enough steam circulating to adequately heat the areas served by the system. This condition can cause sections of the heating system to cool off, leading to cold spots in living spaces. Proper heat distribution relies on the continuous flow of steam, facilitated by the effective operation of components like the siphon loop. Therefore, the lack of effective condensate return and steam flow is directly responsible for the decreased heating efficiency in the occupied areas of a building.