Rinnai RUR98i - Tapping / Vibration Noise

[Temple]

HI,

I've had the RUR98i for about 3 years and it's recently started to regularly vibrate. The noise from the vibration is quite noticeable, but not terribly loud. It seems to be internal to the unit (but I'm not 100% sure).

There is a gap of about of about 10 mins between each vibration cycle and it lasts for about a minute.

There is no need to be using water for the cycles to occur.

I've attached a short recording -

I would appreciate any thoughts.

Thx!

p.s. the unit was flushed about 3 months ago

 

[John Gayewski]

Fan sounds like the fan for the exhaust to me.

 

[Sponsor]

 

[Fitter30]

When it's happening turn power off to the heater, turn valve off and try other valves that should narrow the problem down from a solenoid hammering to check valve. Just one thing at a time. Flushing is one thing should be cleaned out by pumping vinegar through it.