Vokera 20-80 RS Pressure Vessel Pressure

[chrisdicko]

Hi,
My pressure vessel isnt working correctly, and looses its pressure gradually over about 6 weeks. An engineer came to do it last time, but charged a fair bit for not doing a lot!

Whats the process of repressurising it? Just remove any air still in there through the schrader valve, then attatch a bike pump and pump it back to the correct pressure (What is this?!?!), then open the cold water feed until the boiler water pressure is back around 1-1.5Bar?

Im going to have to keep doing this until I can afford to get it fixed correctly or buy a new one. The PRV was ruled out as the problem.

Thanks
Chris

 

[Agile]

Look in the FAQ for general instructions.

However, before you do anything else, press the centre pin in the air valve and let ALL the remaining air out and see if any water comes out as well.

When you have repressurised the air to 1.0 Bar you need to put the water to 1.5 bar.

Before you refit the air valve cap put a little saliva on the valve to see if its leaking.

Tony

 

[chrisdicko]

Thanks, I Had a good read of the FAQs, but aren't too sure about this:

Drain enough water from the heating system, via a drain cock, to allow the pressure gauge to drop to Zero, then let an extra 10 litres of water out, or leave the drain cock open if none will come. This may draw air into the system

Does that deffo need doing?? As im sure when the British Gas engineer was here he didn't do that.
If it deffo does need doing, what does the drain cock look like? Its says let an extra 10 litres out.........will there be 10 litres in there?! As its a combi boiler.

Im 99% sure the pressure vessel is knackered and needs replacing, but I cannot afford anything at the moment and it seems the pressure vessel only needs air putting back in every 6 weeks or so, so I can live with this for a while.

Thanks

 

[Agile]

Does that deffo need doing?? As im sure when the British Gas engineer was here he didn't do that.
If it deffo does need doing, what does the drain cock look like? Its says let an extra 10 litres out.........will there be 10 litres in there?! As its a combi boiler.

We only tell you to do it because it needs to be done!

Its up to you to decide to follow our advice or not.

Dont assume a BG engineer has done something properly.

Tony

 

[scatmanjohn]

The BG enginner will most likely have just opened the pressure relief valve whilst doing it (or maybe not)

If you are with BG why are you on here attempting a diy fix?

I have never had to change one on this boiler and i visit a lot of vokeras.

Why are you 99% sure its knackered, have you checked the schraeder valve for leaks?

 

[chrisdicko]

I'll have to pay BG to fix it again if they come out, and cant afford to get them out again. They do offer a 21 guarentee on their work, but its well past that since they fixed it.

Sorry Agile, I didnt mean that to sound lazy etc on my part. Just im not sure where this valve is etc. And because the BG engineer didnt do it I thought it may not be vital to do. But I'd rather do everything correct like it says. Is there actually around 10 litres in the boiler? Also, when I do drain it and fill it back up, this is just from the cold water feed, and fill it back between 1-1.5bar like it says on the boiler?

scatmanjohn, I just thought it was the pressure vessel as that was the BG engineers thought.....so I just took his word I will have to check the schraeder valve when I do it to see if it is that. When I looked at the valve though, it seems like its fixed to the vessel, so I wouldnt be able to change that anyway would I?

Thanks for the help guys

 

[scatmanjohn]

Hold on...lets start again.

What is actually happening.

Why do you think the expansion vessel is faulty.

Tell us the symptoms of your problem.

 

[chrisdicko]

Well, Ive just bought a new flat (hence having no money), and when I moved in the pressure guage read zero. So I opened the cold water feed and put the pressure to 1.4Bar (said on the boiler between 1 and 1.5Bar).

Now, the boiler wouldnt fire up so I got British Gas out, and it turned out to be a fault air pressure switch or something.

Everything worked well for a few days, but then the pressure had gone back to zero. So again I filled it up and used the heating and hot water, but the pressure guage was going up to 3 bar which I knew was wrong.

Now obviously the water will be going out the PRV (if thats where it going!), but I cant see the outlet anywhere!! My boiler is in the middle of the building, under where my washing machine is. So all I can think is the overflow goes in to the drain for the washing machine!

Anyway, I got BG out again saying they hadnt fixed the fault (although this was actually a seperate thing I didnt let on). So the guy came, and I explained everything as above, and he said it was the Pressure Vessle.

He located it at the top rear of the boiler, and I heard him release a tiny bit of air, and im not sure if a small bit of water came out. Then im not sure if he drained anything or not (like it says in the FAQ's). He attached a foot pump, pumped it up to pressure, and filled the system up to 1.5Bar via the cold water feed.

He put the heating on etc and everything was fine!!!

But over time the pressure on the water guage has been dropping slowly. In about 6 weeks its gone from 1.5 Bar to 0.8Bar.

As ive got no money for a new vessle/boiler/gas man, I was just wanting to try to put more air in the the pressure vessel to try and make it last 6 weeks again. I dont mind doing this every 6 weeks until I can buy a new one.

Thanks for reading this far
Cheers

 

[Agile]

Also, when I do drain it and fill it back up, this is just from the cold water feed, and fill it back between 1-1.5bar like it says on the boiler?

What I said was:-

""When you have repressurised the air to 1.0 Bar you need to put the water to 1.5 bar. ""

I dont say these things for fun and if you are serious about fixing your boiler you would be well advised to do EXACTLY what I say!

I dont agree with that bit in the FAQ about letting another 10 litres come out as usually it will not anyway. It was not me who wrote it! All you have to do is keep the drain point OPEN while you are repressurising the air.

The total system volume is usually 60-100 litres!

Tony

 

[chrisdicko]

Ok thanks Tony. Where do I find the drain valve? I know that will sound dumb, but ive never looked at boilers before. How will I know its open, would the remaining 0.8Bar of water in there drain down? Hence I'd know ive opened the right valve.

Cheers

 

[Agile]

Ok thanks Tony. Where do I find the drain valve?

You may find it on a pipe to one of the downstairs radiators?

But just like I dont know which drawer you keep your socks in*, I dont know which rad pipe your drain cock is on as I dont think I have ever visited your property.

A lady got quite annoyed with me on the phone because I was unable to tell her where her stop cock was located! """You are a plumber, you should be able to tell me!"""

If anyone calls me a plumber I am less inclined to fix their boiler!

And if they tell me to go to their tradesman's entrance I just go back to my van!

Tony


* Are your socks in the third drawer down?

 

[chrisdicko]

Top Drawer

I thought the drain valve was maybe on the boiler somewhere. Obviously not! There is one radiator with a valve on it. Looks like the valve on the left, but mine has been soldered on to the vertical pipe on the outfeed side of the radiator.....is that it?

I presume opening that allows water out? If so how much about, as its quite low to the ground, so wont get much of a bowl under it. Do I close the valve just before this drain valve?

Cheers

 

[Agile]

Open drain part leaving all other valves open.

Use a hose or shallow dish!

Top drawer contains bras!

Second pants and pantees!

So logically the socks will be in the third or bottom drawer!

Tony

 

[chrisdicko]

Socks then boxers........no bra's here Well, I've told her she isnt moving in until ive had my flat a while!

Thanks for the help, I'll get hold of a pump tomorrow with a guage and give it a go

Thanks for all the help and pointers.

 

[scatmanjohn]

But over time the pressure on the water guage has been dropping slowly. In about 6 weeks its gone from 1.5 Bar to 0.8Bar.

But is it still going up to 3 bar when you run it on the heating?

If not then your exp vessel is fine and you have a small leak somewhere.