GlowWorm 24Ci drips water from component (see photo)

[JimboMarimbo]

Drips about half a saucer per day - but enough to lose pressure and need topping up every couple of days.
Anyone can tell me what this component is?

Is it possible to 'adjust' this component i.e. stop it dripping - or it needs replacing?

 

[Agile]

That component is designed to leak slightly but only during filling.

If its leaking when the filling valve is closed then the non return valve part is faulty and has to be replaced.

But if just a few cc of water is causing the pressure to reduce then the expansion vessel needs attention as its not functioning properly.

You may be losing water from your system as well as that valve and could need to solve that problem. Look at the FAQ on this site.

Tony

 

[JimboMarimbo]

Thanks Tony, I'll check the FAQs...

 

[JimboMarimbo]

I've given the FAQs a thorough reading. Bearing in mind your (Tony's) comment that the 'component' in the photo is designed to leak a little when repressurised, I should be looking elsewhere for signs of leakage.
The PRV seems OK as there is no sign of any water around the outside 'overflow' pipe.
In the old house where I live, the pipework is mostly underfloor, and ripping up the floorboards would be a real chore. I am therefore eager to ascertain whether the presumed 'leak' is in the boiler itself or in the pipework.
From the FAQs comes this suggestion:
"Get the pressure up to 1.5 bar then shut the central heating isolator valves (both of them) where the central heating pipes go into the boiler, then wait. If the pressure doesn’t drop then you know the leak is somewhere on your system, if it does drop then the fault is in the boiler."
That makes sense to me, but I would appreciate a professional's opinion on the safety aspects of shutting the CH isolator valves - presumably with everything else switched 'off'. And would it do the trick?

 

[Agile]

That is a good way.

That part is only designed to leak WHILE the boiler is being repressurised, not all the time.

If the expansion vessel is working correctly then the boiler should be able to leak about a litre of water before it goes outside the normal range of say 1.0 to 1.5 bar.

But the function can be tested by filling cold to 1.5 bar and letting heating get hot and see what the increase in pressure is. Should be only abou 0.4 bar.

Tony

 

[JimboMarimbo]

Tony, I'm grateful for your 'function test' information. Which I have immediately tried out.
I filled the cold boiler to 1.5 bar, and then ran the CH for 15 minutes.
At this point the readout was flashing 3.2bar. I switched it off!
I'm sure this will be meaningful to you Tony - perhaps this has been happening for sometime without my noticing. And the prv sending water expelled outside - I have not checked the overflow pipe at night, which is the only time I have used the CH of late. This would explain the 'missing' water.
But what is the cause of the massive pressure build up, would you say?

 

[JimboMarimbo]

Bingo! Have just been outside and shone a light on the overflow pipe - sure enough it is dripping!
Many thanks to you for the 'test of function' info. I now have lots more symptoms which finally make some sort of sense.
I'll go back to the FAQs with different search criteria.
If you yourself have time, you might point me to, what, in your experience, will be the likely cause.

 

[Agile]

I already have alluded to the expansion vessel.

The traditional way to test the pressure relief valve vent for leak age is to tie a bag over the end and check it the following day.

Tony