vokera excell 80sp expansion problem

delaol · 24 Mar 2008

Hi, im new to this site and have found it extremely useful so far !

When i use use my CH the pressure at cold is just above one bar.
But by the time the heating is at full tempreture 60 - 65 , and stays there, the pressure is around 2.5 - 3 bar.

This can't be right, i assume i have a problem with the expansion chamber.

If so, can i recharge it or clean it, or is it better to change it.

Or is it something else?

Your comments would be appreciated, thanks !

Agile · 24 Mar 2008

Just follow the advice in the FAQ section and repressurise the vessel!

Ignore the nonsense about draining a further 10 litres though!

Tony

DP · 24 Mar 2008

I would have thought draining 'another 10l' from the system makes good sense. Afterall, 10 litres missing from the system would be taken up by the 10 liters sitting in the expansion vessel.

ChrisR · 24 Mar 2008

It helps to get the PV empty. Do you call everything you don't understand "nonsense"?
When you build up a little knowledge and experience perhaps YOU would be able to write a FAQ on something?

GasMan1965 · 24 Mar 2008

You need to check that the diaphragm has not split,, if you push on the valve of the expansion vessel does water come out???
If yes then you need a new vessel,, you can also fit another vessel of the correct size to elsewhere in the system if the original is too hard to get @ !!

Agile · 24 Mar 2008

ChrisR said:
It helps to get the PV empty. Do you call everything you don't understand "nonsense"?
When you build up a little knowledge and experience perhaps YOU would be able to write a FAQ on something?

Since the EV is pressurised with the system open to the air then any remaining water will be forced out.

That bit about 10 litres is confusing to DIYers, difficult to do and if it were done would result in air in the system.

Tony

nickso · 24 Mar 2008

Agile said:
ChrisR said:

It helps to get the PV empty. Do you call everything you don't understand "nonsense"?
When you build up a little knowledge and experience perhaps YOU would be able to write a FAQ on something?

Click to expand...

Since the EV is pressurised with the system open to the air then any remaining water will be forced out.

That bit about 10 litres is confusing to DIYers, difficult to do and if it were done would result in air in the system.

Tony

unfortunately i have to agree with tony. the easiest way to do it is to open the prv, pump the vessel and close the prv. no fuss.

it wont necessarily mean air in the system if its done another way though.

GasMan1965 · 24 Mar 2008

nickso said:
Agile said:

ChrisR said:

It helps to get the PV empty. Do you call everything you don't understand "nonsense"?
When you build up a little knowledge and experience perhaps YOU would be able to write a FAQ on something?

Click to expand...

Since the EV is pressurised with the system open to the air then any remaining water will be forced out.

That bit about 10 litres is confusing to DIYers, difficult to do and if it were done would result in air in the system.

Tony

Click to expand...

unfortunately i have to agree with tony. the easiest way to do it is to open the prv, pump the vessel and close the prv. no fuss.

it wont necessarily mean air in the system if its done another way though.

But could quite probably bugger up the PRV and need a new 1 coz it wont stop dripping after

nickso · 24 Mar 2008

GasMan1965 said:
nickso said:

Agile said:

ChrisR said:

It helps to get the PV empty. Do you call everything you don't understand "nonsense"?
When you build up a little knowledge and experience perhaps YOU would be able to write a FAQ on something?

Click to expand...

Since the EV is pressurised with the system open to the air then any remaining water will be forced out.

That bit about 10 litres is confusing to DIYers, difficult to do and if it were done would result in air in the system.

Tony

Click to expand...

unfortunately i have to agree with tony. the easiest way to do it is to open the prv, pump the vessel and close the prv. no fuss.

it wont necessarily mean air in the system if its done another way though.

Click to expand...

But could quite probably b*****r up the PRV and need a new 1 coz it wont stop dripping after

lol, i was waiting for this. in most cases if the exvessel needs repressurising then the prv has most likely been open anyway and may or may not be buggered as a matter of course. sometimes they can be cleaned but as you know if the rubber bit is perished then its a new one.

i always check the prv on any boiler if im working on the water anyway as its a quick check. i would estimate 7/10 prv's that i check are knackered if ive not already changed them, some only need a clean.

i must admit that i have the luxury of a large stock of prv's that neither i or the customer are going to be paying for so it makes the decision easier.

GasMan1965 · 24 Mar 2008

Secret stock

Dont most unvented boilers have a drain point ?

nickso · 24 Mar 2008

GasMan1965 said:
Secret stock

Dont most unvented boilers have a drain point ?

yeh but that involves a hose/bucket/whatever

heatingman · 24 Mar 2008

Do these PRV's just breed in back of van or does somebody have to pay for them.

GasMan1965 · 24 Mar 2008

nickso said:
GasMan1965 said:

Secret stock

Dont most unvented boilers have a drain point ?

Click to expand...

yeh but that involves a hose/bucket/whatever

nickso · 24 Mar 2008

heatingman said:
Do these PRV's just breed in back of van or does somebody have to pay for them.

they arent nicked, but im not paying

delaol · 24 Mar 2008

GasMan1965 said:
You need to check that the diaphragm has not split,, if you push on the valve of the expansion vessel does water come out???
If yes then you need a new vessel,, you can also fit another vessel of the correct size to elsewhere in the system if the original is too hard to get @ !!

OK, thanks for the replies, i assume the valve was the small looking valve that looks like a valve on a wheel of a car.
Which had a little black plastic cap on it, that was looselly fit with a small hole in it. Which was on top of a brass thing connected to the top of the pump.

Anyway i pressed the valve and water shot out ( pressure was at 1.5 bar)

So do i need to change the expansion vessel ?

If so it looks like i need an expert, because it looks like a git to change as its at the back of the boiler near the wall, no bigger than the size of a book.

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

vokera excell 80sp expansion problem

Similar threads