Vaillant 831 Pressure Building

[vigmandingo]

Hi,

I have a Vaillant 831 and the pressure is rising overnight to +3, and to reduce I am removing over 1 ltr of water from the system each day. (seems to be easier to do this from the filling loop when disconnected)

I have disconnected the filling loop, there is a small drip from the water inflow side (but not significant and would not relate to the amount i am removing each night), and a much greater flow from the CH side so I assume that whilst the taps are faulty - this isn't the issue.

I have removed the plastic tap heads and attempted to tighter from the brass valve itself, but this has no effect.

I had the boiler fitted 3 years ago, but it seems from Vaillant that I only had a 2 yr g'tee!

Any ideas (heat exchanger issue?) - is there a test for this? Any idea on cost to replace? I will obviously get a plumber round today, but would be nice to know what is going on.

Thanks in advance for any replies

 

[PrenticeBoyofDerry]

Try leaving the filling loop disconnected and see if the problem is still occurring. obviously you will need to repair the drip on the inlet side of loop.

 

[Terry lambert]

Have you left the filling loop disconnected, and the pressure is still rising ?

It doesn't take a lot for these to let by and cause this fault

 

[vigmandingo]

Thanks for the replies.

I have left the hose disconnected today. but the drip from the ch side is quiet fast so the pressure is actually reducing!

I thought i would cap these valve ends off, fit a cheaper flow valve to the incoming pipes (seems that these valves are notorious) and see how we go. As you say, they need fixing.

My concern was the amount if water i am removing from the system is a good liitre plus some more, the drip from the water inlet side is pretty minimal, presume that suggests this is not the issue? Your views?

I have someone coming over today, but of course i want to minimise call outs as much as possible.

 

[Bunnyman]

U hav found the fault an the reason , it's common an won't be anythin else

 

[vigmandingo]

Taps faulty. Capped them off.
Diverter faulty and leaking - new one fitted

Thanks for the responses, much appreciated.