Vokera 20-80 RS Flowmatic

[ollyfly]

Hello everyone and seasons greetings,

Background: I have recently fitted a new bath in my flat and whilst doing this i was required to turn off my boiler to isolate the hot water. Now that all is back on i appear to have a problem with the central heating side of the system.

Boiler: I have a Vokera 20-80 RS Flowmatic manual: http://vokera.co.uk/wp-content/uplo...c_installation_and_servicing_instructions.pdf

Problem: I pressurise the system to 1.5 bar, i can then run the central heating system with no major change in pressure (it may loose a little) but after i switch the central heating off the pressure drops to zero over a time (hours not days; usually over night when i am in bed).

Questions: Do i need to "re pump" the expansion vessel to 1bar as per the FAQ section on this site?

If so how easy is it to get at for this boiler?

Does it matter that my flow loop only has one tap on it and is permanently connected to the boiler! (Picture attached)

Hope someone out there can please help, i am in danger of being made a single man via a rather cold mrs!

Cheers Olly

Boiler Filling Loop

• ollyfly
• 27 Dec 2011
• 1

 

[45yearsagasman]

Access to the schraeder valve (to check and if required pump up) the exp vessel is at the top rear of the boiler. Ensure the system pressure is zero before checking precharge, and if necessary pump it to approx 12psi and then refill system via fill loop. The loop should technically be disconnected to comply with water regs, but are normally left connected for convenience.
There is only one tap on yours and the other end is a non return valve.
You should also check that your pressure relief valve is not dripping to outside. Hope this saves your marriage!

 

[ollyfly]

Thanks for that I will have a go.

Just a few quick questions before i attempt this...

Where is the drainage tap located to allow me to release the pressure from the system?

Is it here where i am required to drain 10 litres of water from too? (as per the FAQ)

Thanks again,

Olly (marriage saving is on going...)

 

[twgas]

I dont think the flowmatic has a built in drain off (might be wrong there!), you need one on the system, normal drain cock.
connect hose, open drain cock, ignore the 10litre bit, when pressure is at zero pump the vessel up to 0.8-1bar. you will get a bit of water come out the hose while pumping. once pumped do up the drain cock, repressurise and bleed system before firing boiler.

 

[ollyfly]

Thanks Guys,

What should i do if it doesn't have a drain cock? (which i don't think it does).

Olly

 

[45yearsagasman]

You will have to release the system pressure either by a drain cock on the system pipework or rad valve or by the air bleed screw on the rad.

 

[ollyfly]

The wife is kinda talking to me now...

I have released the pressure and the indicator gauge says that it is at zero. In the FAQ it says "it is IMPERATIVE that water or air is allowed to escape from the heating system as it is pumped out of the PV"

Does this mean i need to keep a radiator valve open whilst pumping?

Also - as all the pressure had leaked away by itself from my system, where does it go?! I pumped it up yesterday to 1.5bar and today its at zero... any clues?

Olly

 

[ollyfly]

The wife is kinda talking to me now...

I have released the pressure and the indicator gauge says that it is at zero. In the FAQ it says "it is IMPERATIVE that water or air is allowed to escape from the heating system as it is pumped out of the PV"

Does this mean i need to keep a radiator valve open whilst pumping?

Also - as all the pressure had leaked away by itself from my system, where does it go?! I pumped it up yesterday to 1.5bar and today its at zero... any clues?

Olly

 

[Agile]

Look at the pressure release valve vent.

Put a bottle or bag over it overnight to see if its leaking.

If not then feel all the rad valves and look at your hand for moisture.

Tony

 

[ollyfly]

sorry to drone on about this...

I opened a radiator to let all the pressure out.

I have hooked up a car pump to the PV valve to re-presureise it, initially air came out as opposed to water.(which is good i believe) The pump shows no pressure is currently in the thing.

When i pump no pressure ever registers and i am sure i can hear air escaping from somewhere?!

Any ideas?!

 

[ollyfly]

Anyone know why this might be happening? Have i done something wrong?

Thanks

 

[Agile]

It sounds as if the pressure vessel is failed.

Repressurise the boiler to 1.0 Bar and press the air valve pin. I suspect water will come out.

See FAQ for how to fit a new one somewhere else.

Tony

 

[ollyfly]

I think it might just be leaking at the inlet where i am pumping the air. If i remove the pump quickly i can then press the value and air comes out as normal. Perhaps a new foot pump is what i need.

That all sound correct?!

 

[Agile]

Only you can see what is happening with your footpump!

Both of mine fit boiler and car tyres OK.

You do have to rotate holding lever by 90 degrees to lock it on!

Tony

 

[DP]

Keep pumping and see if there is any change. Often the 'failed vessel sound' is the residual water being forced out of the vessel. Also, takes a while to up the pressure with a foot pump.

I would have suggested the pressure not be reduced to zero when pumping up the vessel as you might encounter complications later

When the red light is on and no demand has even made to the boiler for a while, place your hand above the pilot viewing slot. Is that area hot?