Viessmann vitodens 100

[Nvq level 3]

Hi, was called out to the above boiler because of an intermittent whine coming from it. This whine only seems to happen on the heating demand, I'm not sure if the diverter isn't opening all the was causing this sort of noise or maybe something is in there? when I close off the iso valves this noise stops?? Bit of a strange one! and ideas anybody? thanks (I cant seem to go down a line so excuse the big paragraph)

 

[Neil K]

All I can think of from your description is check the pump. What's the system pressure and how old is the boiler

 

[Nvq level 3]

Pressure is normal at around 1 bar, put my hear to the pump and that sounded fine, just seemed to be coming from the plastic block area, more to the left of this. near the plate to plate and its the older model 5 years or so?

 

[Neil K]

1 bar with full heating on?

 

[Nvq level 3]

well a little over when heating on, but nothing of any concern.

 

[Neil K]

All rad valves open? Did you check the pump? Are the rads heating up?

 

[Nvq level 3]

yep everything is hot and working fine its just a high pitched whine, not the easiest thing to explain I'm afraid. Its only when the heating is on though this doesn't happen on a hot water demand.

 

[Neil K]

Try topping pressure up a bit and see if it makes any difference.

 

[Nvq level 3]

Will give it a go. Thanks.

 

[Neil K]

Turn all rads off, set up a hose on boiler (at top there's a vent just like what you see on a manual vent on a modern rad) and flush it it via cold water mains. Slightly overpressurise it first ( 2.3 bar cold) , flush it both ways with iso valves open and closed both ways and with and without heating on and see what happens. This advice is only to clear a bit of sludge or scale which may or may not be causing the problem.

 

[Nvq level 3]

Will give this a try. Thanks again.

 

[Neil K]

Sorry forgot to say, do it then with all rads open . See if you clear anything ( cold water mains powerflush ). Then with system at 1.3 bar cold fire it up and see how you get on

 

[Neil K]

And if none of that works get on go Vieshmann. If it does work then HAPPY DAYS, recommend a power flush and fitting a magna clean

 

[Deleted member 64964]

I've had a whiny scream coming from a W100b I connected a small power flusher to it and flushed it through with some fx2 both directions and it sorted it out.

The scream on came about over 65 degrees or there abouts.