Kettling boiler - risk running cleaner?

[Lee]

12 yr old Vaillant Turbomax combi boiler is kettling*, although not too badly at the moment. Not entirely sure if this is a gradual build up as only really noticed in the last day or so. Heating and DHW performance seem unaffected. System is sealed and has always had inhibitor.

Asking for opinions really, at 12yrs old is it worth running the risk of introducing leaks by using a cleaner?

Lee

tl/dr:

*was quite noisy fairly intermittently and also specifically above 65C (on display), thought it might be the pump so went around bleeding/checking for air leaks etc. It is now *significantly* quieter (much quieter than an actual kettle) but now "kettles" gently all the time it is lit. Problem is I can't remember if this is "normal" for this boiler :) Plus it could still be the pump...

[Fredxxx]

I've never used cleaner in a heating system so can't offer any advice on that.

If you keep the pressure on the high side, that can certainly reduce kettling.

[Tim+]

And the system pressure...?

Tim

[Lee]

It was at the end of the "green bit" on the gauge @70C when I checked, let's have a look... currently at 1.5Bar @33C so it would have been 2 Bar @70C. Really awkward to get a tyre pressure gauge on the expansion vessel - but that was ok when I checked it a couple of months ago. No air came out any of the bleed points or the pump...

[PeterC]

Same with my slightly older ECOmax when trying an angled gauge, then I remembered a straigh gauge and that was OK. Don't know if such a thing is still available. The real pig is pumping it up - a bike track pump seems best - just don't take it to 8 bar!

[DerbyBorn]

PeterC wrote in news:zpdgyqnlmhjr $.p6wl19v5mflp$. [e-mail]:

Surely the dry side of the vessel should not lose pressure - although it will if it is knackered.

[harry]

Kettling is actually cavitation. Steam bubbles forming and collapsing. Over time it causes damage. Especially to pumps.

First is to check the system pressure. The primary purpose of closed systems is to enable higher speed water flows by means of higher pressure in the system.

So it may have lost pressure and need restoring (ie a bit more water put in)

[harry]

Heh, It's water you've lost not air. Though that maybe because the diaphragm in the expansion vessel is ruptured.