The pump in my system boiler has suddenly started making a variable whooshing noise like you get after a fill when the water has lots of air in it and you can hear the pump cavitation. Infact it sounds more like a dishwasher than a heating pump.
I'm pretty sure there is no air in it. It is a sealed system and the last time I added any water to it was about 3 years ago after removing a rad to decorate. The highest radiators in the system have no air in them and the the auto air vent by the hot water tank is hot right at that top indicating it has water in it, not air.
The pump (head) is a Grundfos 15-60 and it is about 12 years old as is the boiler. I don't want to replace it unnecessarily, and I can't think of what would suddenly cause it to start making this noise. There are no other symptoms as far as I can tell.
Anyone got any ideas?
I'm pretty sure there is no air in it. It is a sealed system and the last time I added any water to it was about 3 years ago after removing a rad to decorate. The highest radiators in the system have no air in them and the the auto air vent by the hot water tank is hot right at that top indicating it has water in it, not air.
The pump (head) is a Grundfos 15-60 and it is about 12 years old as is the boiler. I don't want to replace it unnecessarily, and I can't think of what would suddenly cause it to start making this noise. There are no other symptoms as far as I can tell.
Anyone got any ideas?