vaillant ecotec plus 824 combined intermittent fault.

northcarr · Jan 26, 2014

Had a chap on the phone with an ecotec 824 the pressure on the gauge is going into the red when the boiler is first fired up on heating and the rads are scorching after about 20min all is fine,this only happens every few days apparently. My first thought's are expansion vessel pressure or packed up ,or blockage with crap in the expansion vessel hose ,there are no fault codes coming up just wondering if there are any common faults with these boilers as I don't do many repairs thanks in advance for any help .

IDCHAPPY · Jan 26, 2014

If the expansion vessel was horsed the pressure wouldn't return to normal when the system was warm.
Something odd going on, i take it he's not needing to top up the system or hasn't spotted any water out the blow off pipe?

northcarr · Jan 26, 2014

IDCHAPPY said:
If the expansion vessel was horsed the pressure wouldn't return to normal when the system was warm.
Something odd going on, i take it he's not needing to top up the system or hasn't spotted any water out the blow off pipe?

No I asked him he hasn't had to top the water up it's a bit odd this one.

Ermintrude · Jan 26, 2014

Pump is modulating down after 20mins and pressure dropping back. and the system is probably a little too big for expansion, so with thermal and kinetic pressure rise the needle just hits red. Check vessel charge and calculate system volume.

northcarr · Jan 26, 2014

Ermintrude said:
Pump is modulating down after 20mins and pressure dropping back. and the system is probably a little too big for expansion, so with thermal and kinetic pressure rise the needle just hits red. Check vessel charge and calculate system volume.

The boiler has been in since 2008 so I think it could be the charge pressure but it seams strange that it settles down after a while.

northcarr · Feb 3, 2014

The expansion vessel had no pressure in typical ecotec and the epansion pipe that goes into the hydrblock was blocked with crap what Muppet desided to make it out of what appears to be 10mm copper pipe ffs and put it where there is next to no access .