We had a combi boiler that has now been replaced by a combi new boiler last year. Both have the same symptoms.
The old boiler was set to 1 bar pressure. This new one sits at 1.5 when the CH water is cold. Both maintain pressure until I bleed a towel rail then the pressure drops. Both systems are and were fully dosed with inhibiter. A match test reveals no gases.
Now the question. I can grasp the fact that a leak will drop the pressure but I can’t grasp how a pressurised CH system can leak water over time that is replaced by air of equal pressure.
This has been happening now for 16 years. Do I really have a leak or is some magic occurring?
The old boiler was set to 1 bar pressure. This new one sits at 1.5 when the CH water is cold. Both maintain pressure until I bleed a towel rail then the pressure drops. Both systems are and were fully dosed with inhibiter. A match test reveals no gases.
Now the question. I can grasp the fact that a leak will drop the pressure but I can’t grasp how a pressurised CH system can leak water over time that is replaced by air of equal pressure.
This has been happening now for 16 years. Do I really have a leak or is some magic occurring?