Vaillant Ecotec plus high pressure

[davehurry]

Hello,

I've recently noticed the pressure of our 3yo Ecotec plus 824 rising for no apparant reason. I've only ever had to top it up a handful of times since installation but it had gone up to 2.5bar so after releasing some pressure and getting it back to 1.6bar last thursday it has gone back to 2.5 by Sunday morning. It was also serviced on Thursday and had the expansion vessell topped up with no obvious problems (it had been rising before the service too just to be clear).

I've got no error codes and no obvious leaks so could the water be coming in via the filling loop?

Both valves are closed off but is there a way of checking these/tightening them up? I'm in the middle of experimenting for the next few days - I'm turning the mains water off overnight and during the day when we are out to see if is definitely the filling loop. When the CH is on it behaves normally, going up about .3bar.

Anyone else experienced something like this or have any other possible explanations?

Thanks

 

[kevindgas]

is there a 2nd filling loop (braided type) in addition to the ones under the boiler? if so did your plumber use it instead? and then not turn off correctly?

 

[davehurry]

No 2nd braided loop, just the standard pair of valves and they appear to be fully turned ff.

 

[xr4x4]

So the pressure is rising without the system being on?

The filling loop must be passing. Turn the tap off and disconnect it, their should be no water coming out.

If it's rising when on, sounds like expansion vessel problem.

 

[davehurry]

xr4x4,

The pressure is rising significantly when the system is off.

When the heating is on it goes up a little (0.2-0.3) but that's normal right?

I don't undertsand what you mean when you say 'turn the tap off and disconnect it'.

 

[picasso]

The plastic handles on these arent the best, unscrew the handles (there is a small screw in the middle ) and shut off the valves using a small spanner.

 

[davehurry]

Picasso,

Thanks.
I did have that thought as I was looking at it this morning.
I'll give that a go when I get home and see if they are not fully closed.
I suppose it could be the double check valve itself which is letting water pass.

 

[xr4x4]

On the filling loop to the boiler (the felixy line)

 

[davehurry]

Ok apologies for me being a little stupid.

There is a flexi hose on the loop, I obviously wasn't looking closely enough.
I think I have sorted it now.

I disconnected the cold return side and there was a slow drip still coming through the hose from the mains when both valves were fully closed off. I tried turning the mains open/close with a spanner and it did not stop so I then turned the other valve ( right next to mains side, possibly service valve?) each way to make sure it was also tight and hey presto, the drip from the mains seems to have stopped. I let it dry out properly and no more drips... so far so good.
If it happens again it is the valve itself which is connected to the mains - is that the double check valve?. I'm just pleased that it is not too serious.

Thanks for the tips.

 

[Agile]

I still dont understand if you are dealing with the inbuilt boiler filling loop or oine under the boiler on the pipework.

In either case the isolating valvews can leak and many have wear on the plastic knob which prevents it from closing properly.

Of the boilers I visit perhaps a third dont shut off correctly by using the plastic knob. I usually remove the hose to check the situation.

Tony

 

[Bunnyman]

Right Dave the ecotec fill loop is a known fault and they do pass I do 2 or3 a month,u can't repair em just change it they about £35 for the mains inlet side It seems u just disturb em an they pass

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• Bunnyman
• 26 Mar 2010
• 499

u prob found out by now that u got no hot water flow with the isolating valve u turned off

 

[davehurry]

It's the loop on bottom of the boiler - two open/close valves with plastic knobs and a flexihose connecting them.

I turned the isolating valve off and then on again, that is when the drip stopped. Hot water/CH is fine.
Handy to know it's a known fault.
The plastic knobs are crap also, doesn't take much to break them.

To change the valve does the system need to be drained?

 

[Agile]

The system isolating valves under the boiler can be turned off and just the boiler drained.

The cold supply also has to be isolated.

I assume you did try turning the metal shaft after removing the plastic knobs?

Tony

 

[Bunnyman]

ur wrong tony! the flow isolating valve has the fill tap connected to it so u cant isolate and change this valve without draining the system unless u risk it holding on an airlock

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• Bunnyman
• 26 Mar 2010
• 499

 

[davehurry]

Agile,

yes I did try using a spanner to turn the valve but it was starting to come out quicker the tighter it went and i didn't want to break it!

I plan on changing the inhibitor soon so may as well look into changing the valve then when it is all drained out. It's been fine since yesterday but I'll be keeping an eye on the pressure for a while.