Vaillant EcoTecPlus Overpressurising Only when in Use

[The Rig]

Hi Guys, i come on here a broken man LOL

Ive got a 4 yr old Vaillant EcotecPlus 831 combi boiler that over the last 2 months has been overpressurising when the Rads are on and has got worse now to the point it maxes out the pressure to 3.5 Bar the PRV opens, lowers the pressure to about 3.1 Bar, the rads still operate etc, but then, when the CH is off the pressure drops to 0 Bar but i cant find any leaks in the system !!!!!!

What i have tried so far....

When Cold, i set the pressure via the filling loop to 0.6 Bar, when CH is on, still maxes out to 3.5 then drops to 0 when cold
I have bled the rads in case any air in them, none present
I used a footpump and re-charged the expansion vessel, i put about 0.5bar into it, i used the digital gauge to see how much each pump of air from the footpump increased the vessell, still no change with the problem

So, any ideas guys ???

Cheers

 

[stevetheplumber]

blocked pipework to the pressure vessl

 

[The Rig]

Cheers bud, will check for that

i just want to double check im re-charging the Expansion vessel correctly (probably not LOL) my dial gauge and digital gauge built into the boiler read 0, so i pump the vessell upto about 0.7 Bar, but when i do this, the pressure gauge and the digital gauge increase and read 0.7 bar (digitally) and just under 1 on the analogue gauge, now should this happen ? i thought the expansion vessel should be charged up but not affect the pressure of the readings ?!! As when i charge the vessel up i dont need to use the filling loop to increase the pressure as its already reading 0.7 bar etc ?!?!?!

Even tho my readings are 0 on the dials of the boiler when i begin, should i be bleeding out a litre of water from the radiators to remove all water from the vessell ?

cheers again

dean

 

[dancinplumba]

Need a GSR to sort this out, please call one in

 

[Dotty]

Agreed.

You need a gsr in to look at your boiler. We cannot and will not give advice on the installation or repair of boilers for your own safety.

Please go to Gas Safe Register | Ensure your gas engineer is registered. or post a thread in the 'I'm looking for a plumber / gas engineer' section of these forums remembering to include your location. [DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas Engineer[/DLMURL]

If you are gsr please increase your post count to 10+ then send a pm to either Gas man or Redsaw who will then check you and then give you access to the gsr private forum.

Thank you.

http://www.ukplumbersforums.co.uk/central-heating-forum/42241-notice-gas-safety-related-advice.html