Water hammer - MegaFlo tank

[wardr77]

Recently noticed what appears to be water hammer in the pipe work when using the shower. Its a loud vibrating noise that last for approx 4-5 seconds stops and then starts again after about 20-30 seconds all the while the shower is on. Doesn't do it when the hot taps are used. In the downstairs shower the noise seems to come from above, definitely not next to the shower.
Also the noise occurs whether the heating / hot water is on or not. Recently had a new pump fitted but cant see that would be the cause. The hot water comes from a Megaflo cylinder located upstairs. Any advice or suggestions to resolve would be much appreciated.

Many thanks

 

[Madrab]

When was the last time the unvented was serviced?

 

[wardr77]

probably about 2 yrs

 

[Madrab]

UV might need a service/air bubble checked. It may be what the issue is if but if not, hopefully whoever is looking at it is experienced enough to understand what's causing it.

 

[wardr77]

Thanks, I did wonder about the air gap on the Megaflo, I did look at the Tundish and although not dripping, it is wet to the touch. The instructions seem fairly straightforward to recharge the airgap, so may give that a go and see if it does anything

 

[Madrab]

Yup, if you feel handy, re-charging the bubble is a self service operation.

 

[JohnD]

veering off a bit, it sounds like the Megaflow internal bubble is more troublesome than the separate, external pressure vessel on other designs.

Have I got that right?

 

[Madrab]

It can be, hence why I think they allow the customer to re-charge it themselves.