A Typical Open Vented Heating System Without Heat Hero
All open vented heating systems should have a small storage tank in the attic which gives approx. 0.5 bar of pressure in the heating system.
When the CIRCULATING PUMP IS INSTALLED ON THE RADIATOR RETURN this circulates the water through the solid fuel boiler towards the open air vent. This results in the 0.5 pressure being pushed out of the heating system and removes all of the pressure from the heating system, slowing down circulation and affecting the efficiency.
Also, when the CIRCULATING PUMP IS INSTALLED ON THE RADIATOR RETURN there is no circulation around the cylinder when the pump is switched on. This means that the only way to heat the hot water cylinder is with gravity. This is very slow and inefficient.