Hello I wonder if anyone here can help. I have an Ariston Microgenus 23mffi combi boiler that is reasonably old, maybe 6 years, possibly more. It was in the flat when we moved here.
The hot water through my shower (or any high flow like the bath) starts off hot for a few minutes and then cools to luke warm. There doesn't seem to be any problem with the central heating and the boiler delivered hot water at a high flow rate with no issue prior to the fault developing. The pressure sits at 1.0bar and moves to 1.5 during water demand and doesn't need regular topping up
When I turn on the shower the pump and fan start and the burners ignite and a large flame is visible. The lights on the temperature LED panel start to light up and reach the 4th or 5th one, it continues to heat for a little while like this (hot shower) and then the gas flame reduces down in turn the temperature LEDs start turning off and go down to one or two (shower temp cools to luke warm)and is stays like this while water is being drawn. When demand for water stops all the LEDs go out the pump and fan continue to run the burner stays with a low flame and there are quiet noises from the pump like water bubbling/boiling then the fans, flames and pump stop and all the lights on the LED temperature display light up showing 80C. when left these lights start to go out slowly one by one.
At first I thought the heat exchanger could be blocked so i changed it. The one i took out looked quite dirty. I also changed the hot water thermostat. When i refilled the system i put in some cleaner left it for while and have since emptied and refilled the system a few times before refilling and adding an inhibitor.
The problem still exists i wonder is anyone had any other ideas?
The hot water through my shower (or any high flow like the bath) starts off hot for a few minutes and then cools to luke warm. There doesn't seem to be any problem with the central heating and the boiler delivered hot water at a high flow rate with no issue prior to the fault developing. The pressure sits at 1.0bar and moves to 1.5 during water demand and doesn't need regular topping up
When I turn on the shower the pump and fan start and the burners ignite and a large flame is visible. The lights on the temperature LED panel start to light up and reach the 4th or 5th one, it continues to heat for a little while like this (hot shower) and then the gas flame reduces down in turn the temperature LEDs start turning off and go down to one or two (shower temp cools to luke warm)and is stays like this while water is being drawn. When demand for water stops all the LEDs go out the pump and fan continue to run the burner stays with a low flame and there are quiet noises from the pump like water bubbling/boiling then the fans, flames and pump stop and all the lights on the LED temperature display light up showing 80C. when left these lights start to go out slowly one by one.
At first I thought the heat exchanger could be blocked so i changed it. The one i took out looked quite dirty. I also changed the hot water thermostat. When i refilled the system i put in some cleaner left it for while and have since emptied and refilled the system a few times before refilling and adding an inhibitor.
The problem still exists i wonder is anyone had any other ideas?
