Leak in Combi CH

[kevhky]

yes its the same prob as before thought id start a new post as id thought problem had gone when i put f4 in system but it never fixed the problem,

Expansion vessel ??

 

[fazedup71]

if it keeps going above 3 bar then yes!

 

[kevhky]

When heating is running it reaches around 3bar the cuts off, Nothing is released via PRV

So this leak if in boiler could either be 2 things, Heat exchanger or expansion vessel or 3rd the pipework leading to the rads.

Is it easy to replace heat exchanger and expansion vessel i am fairly handy or is a job for the pro

 

[Agile]

Have you actually put a bottle, plastic bag or condom over the PRV vent?

Most boiler leaks from Vokeras are small leaks at joints and the water just gets boiler away so it is not seen leaking out of thecasing. One wonders where your Barclays fellow has been all his life.

Pressurise your boiler to 2 Bar and close the boiler isolating valves and see if pressure falls but dont use it during about 2-3 hours.

Tony

 

[kevhky]

Have you actually put a bottle, plastic bag or condom over the PRV vent?

Pressurise your boiler to 2 Bar and close the boiler isolating valves and see if pressure falls but dont use it during about 2-3 hours.

Tony

Hi Tony

yes ive covered the prv with a bag, over a week it was bone dry

if i turn off the boiler isolating valves will i not use it at all for hdw also

Kev

 

[Agile]

With the boiler pressurised and the isolation valves closed you could in theory use it for hot water.

I would advise YOU against it though because I am not confident from what you have said that the expansion vessel is operating correctly because you seem to be saying that the pressure increases more than 0.3 Bar when the boiler gets hot.

Tony

 

[kevhky]

Thanks Tony

just to clarify
When i pressurize the boiler to 1bar when CH is running the pressure rises to approx 3bar then the heating switches off nothing is released via PRV when the pressure begins to drop the heating starts up again.

Are all combis fitted with these isolating valves and are they easy accesible

cheers

http://i298.photobucket.com/albums/mm250/kevhky/Combi/52d07d47.jpg

 

[Agile]

What do we have to say to you to get you to understand that the expansion vessel should adsorb expansion and the pressure should not increase by more than about 0,3 Bar from cold to hot ?

There is something wrong!

Have you exactly followed the FAQ instructions to repressurise the EXV ?

Tony

 

[kevhky]

Okay Tony point taken, i will look at the exp vessel today

cheers

kev

 

[kevhky]

Can you confirm this is the expansion vessel im checking although im certain it is just to be absolute sure

http://i298.photobucket.com/albums/mm250/kevhky/Combi/4c2f67af.jpg

thanks

Kev

 

[kevhky]

UPDATE:

Ive checked the expansion vessel and re pressurized to 0.80 bar as per manufacture

When the heating is running now it only rises to 1.5bar from 1bar

Looks like i certainly fixed that problem, i just now need to check that my pressure doesnt drop like it has been

Thanks Tony and fazedup71 for your advice and help

Hopefully touch wood this is the end of my problems

Kev