Unit has been fine for last 6 years but recently has been making a groaning sound when going into high heat phase (2 Stage). Quiets down when getting close to temp but then noise returns briefly when boiler stops firing. It seems like gas valve but Buderus thought it was flow issue and asked me to turn circ pump down to low setting- noise still there.
No noise when heating hot water, low heat mode.
Also sounds a little like a tea kettle the few times it's not groaning during heat cycle.
Just had a tech here but he was no help, still got charged a service call...
No noise when heating hot water, low heat mode.
Also sounds a little like a tea kettle the few times it's not groaning during heat cycle.
Just had a tech here but he was no help, still got charged a service call...