Vaillant Eco tec Plus 831

[rockinter]

Hi,
I recently had a y filter installed on the central heating system (on sealed system). But now after 3-4 hours of the central heating system being on a droning noise starts to come from the boiler as if the pump is struggling. But when I turn on the hot water tap the noise goes away.

Does this mean the pump gets tried from pushing the water through the system? And why does it happen only after 3-4 hours of the central heating being on?

 

[twgas]

sounds as though you've got a lot of cr4p in your system and its blocked the filter.

 

[rockinter]

Thats what i thought it was at first, but once you turned on the hot water tap and it goes back to the central heating system it doesn't make the noise for another 3-4 hours.

If the filter was blocked shouldn't it make the noise constantly once it is blocked and be unaffected by the hot water tap being turned on?

 

[gas4you]

The usual cause of an Ecotec droning loudly, is muck in the bottom of the main HE.

The confusing part here, is that it always does this when on full power for DHW and not only after 3-4 hours of ch use

 

[rockinter]

I was thinking maybe it was the pump getting tired from pumping the water through the y filter and when i turn on the tap it lets pump cool down so the noise goes away.
Is there way to check if the pump is receiving less water in the central heating system? I mean from the LCD display.