Vokera Excell SP80 Dripping overflow

[demondriver]

I'm after a bit of advice folks......

For the last few weeks the pressure has been dropping on my Vokera combi. It is now dropping by almost 1 bar a day.

I took up several floorboards and couldn't find any leaks but I read some posts on here about the 15mm overflow pipe dripping - and sure enough it was.

I let approx 4 litres out of the system and tried to repressurize the expansion vessel and the dripping stopped. Excited about by newly found skills I opened a beer to celebrate but I've just been and checked the pressure (2 hours later) and it's dropped again and the dripping has started

Does this mean that the expansion vessel is damaged or could there be another problem?

 

[kevplumb]

whats the system pressure

 

[demondriver]

kevplumb,

I set it to 1.2 bar and it's down to around 0.4 bar now ( I charged the Expansion Vessel to 12psi )

 

[kevplumb]

first shot change the prv

 

[glasgowgas]

secondly to my learned monkey hanging pal,

try isolating boiler and releasing all the c/h,then re pressurise to 1 bar

while the front cover is off check operation of dhw micro and pump proving micro.

if any of these are slow to return, it will keep boiler firing when no demand

possibly causing it to over pressurise

oh and change the PRV

 

[demondriver]

Thanks for the replies - I'm a complete novice and had no idea what an expansion vessel looked like 2 days ago. This all sounds very tricky/complicated and I might need a chap wearing Vokera overall's to come and sort this out.

I'll keep you posted...

Thank you.

 

[kevplumb]

I let approx 4 litres out of the system and tried to repressurize the expansion vessel

missed this

system or boiler should be empty and open to atmosphere when you recharge ex v

i have the mi's if you e mail me adress in profile

of stick an addy in yours

 

[demondriver]

Hi kevplumb,

Apologies - I'm away from my desktop and don't have frequent access to the net at the moment. E-mail addy completed in profile now.

Will completely drain system and try to recharge to the EV as per your advice.

D

 

[kevplumb]

mi's sent

 

[demondriver]

kevplumb,

Got them - many thanks for the help

The boiler is more than 12 years old now but in its quite reliable life its only had fitted: 1 x replacement fan, a PCB (which I was never sure about!) and a couple of diaphragms. If the EV needs replacing is it worth doing given its age or should I consider a new condensing boiler? Any thoughts welcome

 

[kevplumb]

if its shot but not leaking it might be easier / cheaper to fit a remote vessel

 

[DP]

If a Vokera two generation older than your Excel is still chugging away reliably, I fail to see any reason to replace it. Of course, a service as mentioned in the book is mandatory for reliable operation.

 

[Agile]

I dont see that you have yet repressurised it according to the requirements.

The FAQ on this site gives full instructions. As stated above it needs to be pressurised to 0.9 Bar with the system open to atmosphere.

While you do that if it is seriously failed it will not pressurise at all !

If it does then repressurise the system to about 1.5 Bar and turn on heating and watch the pressure gauge, it should not go about about 1.8 Bar.

If the EXV can be repressurised Ok then the PRV may still drip a little but they often stop after a few days. If not its fairly easy to replace.

Those are getting a bit old but they are still quite reliable and it could give you another few years service. They are still totally repairable and spares are available.

Tony

 

[demondriver]

kevplumb,

Cheers - will consider that as an option.....

DP,

It has been reliable and to be honest, if the boiler hadn't been fitted where it was (cupboard in the back bedroom) - I would never have bothered replacing the noisy fan

Agile,

You're right - I haven't re-charged it as per the instructions but now I'm home from a few days away I'll do the job properly this time