I have an unvented cylinder with the secondary return "circuit" plumbed in on the hot water side with a Grundfos Comfort 15-14 BA PM pump attached.
The issue I have, the pump is 'pulsing' so it runs for a second or two, stops for a second, then repeats this. Sometimes, it makes a slight squealing noise. It does this no matter which mode I put it on.
Video of issue: https://1drv.ms/v/s!As19bM4LfI6tkTr3-d02JHzAgUtq?e=9OjgZR
Any ideas what could be causing this behaviour? My understanding is that the pump should just run constantly. There is a check valve on the flow side.
TIA
The issue I have, the pump is 'pulsing' so it runs for a second or two, stops for a second, then repeats this. Sometimes, it makes a slight squealing noise. It does this no matter which mode I put it on.
Video of issue: https://1drv.ms/v/s!As19bM4LfI6tkTr3-d02JHzAgUtq?e=9OjgZR
Any ideas what could be causing this behaviour? My understanding is that the pump should just run constantly. There is a check valve on the flow side.
TIA
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