Repressurising the Pressure Vessel - Glowworm Swiftflow 80

[scholesy]

I'm curently trying to repressurise my combi-boiler. I've managed to locate the valve, (car tyre type), attached to the mini expansion vessel, (about the size of a tennis ball), and by contorting my arms into very odd angles have managed to attach a pump.

Now when I pump the pressure will rise to say 20 psi but the second i remove the pump all the pressure comes straight back out in an instant! I am trying to remove the pump from the valve as quickly as possible but am not able to leave any pressure in the vessel!

I have closed all the valves going in/out of the unit (gas / water). I've read in the FAQ that you should drain 10litres of water from the system from a draincock but could not find one so left this. Is this causing the problem and if so where will the draincock be? (I did read somewhere else that you didn't need to do this but am now thinking maybe they were wrong)?

any help greatly appreciated

thanks

 

[twgas]

wrong vessel----the one you want is the red on at back of boiler

 

[scholesy]

thanks twgas

I've found the other one were you said. However i've still got the same problem in that as I remove the pump the air escapes and pressure goes to 0. Any advice? thanks

 

[corgiman]

over pump it and move the pump connection really quickly.

 

[scholesy]

OK, i've really struggled with this. The valve is in an awkward spot next to where the Pressure Vessel is clamped. Also using a footpump isn't very easy when you can't use a foot.

I've managed after may attemps to get 0.35 bar into it. I'm hoping this may be just enough although it's well under 0.7. You'd think it would have been designed to make things a little easier.

Thanks again for the help

Andy

 

[corgiman]

boiler makers making boilers easy to work on

thats a novel idea that has never ever occured to them.

 

[twgas]

increase it to 1bar, then the bit of air you lose wont hurt,
dont forget to release all the watr pressure and leave an open joint when repressurizing

 

[scholesy]

I actually increased it has high as I could - I got it to around 2.3bar. But as soon as I release the pump most of the air escapes. Extremely frustrating. I may have another stab at it tomorrow if the 0.3 bar isn't enough.

"dont forget to release all the watr pressure and leave an open joint when repressurizing"

Haven't a clue what you mean by this - I'm a complete novice at plumbing, (but eager to learn). I was just going to repressurise by putting some water into system and topping up to about 0.7 bar. I've not actually released any water from the system.

thanks

Andy

 

[scholesy]

My system is now starting automatically but the pressure rises to 3 bar which is obviously too high. I think I'll redo the repressurising but this time release 10litres of water from the sealed system first. I've found a drain cock on one of my radiators so i'll use that.

If I let 10 litres of water out will i then be able to pump 10litres of air easily into the system before the pressure starts to rise again?

Also will I need to add some inhibator if I'm draining 10 litres of water from the system?

In fact I think the penny maybe starting to drop. If i didn't release any water from my system initially would that explain why I struggled to pump air into the system.

Thanks

 

[WDIK]

vessel pressure is very important, too much and its a rock and a hard place, too little and its a rock and a hard place.
it needs to be the same pressure as the system designe pressure.
if it were a car tyre you wouldnt accept putting some air in as being a solution would you?
if you put 10lts of air in you need to let 10 lts of water out.
and its best done cold.

if the schreider valve leaks go to halfords and get a new insert, if water comes out then go to hrpc and get new vessel.
theres no half way fix, do it right and be safe or get a proffessional to look at it.
your sytem is going to 3bar because the is insufficient capacity for the water too expand when it gets hot. it ejects via the relief valve and goes low pressure when its cold, you then top it back up, doing this will constantly introduce RAW water which will eventually cause all the problems of corrosion and scaling that will wreck your system.

 

[scholesy]

OK points taken

I've now released 10litres of water via a drain cock on a radiator. Still struggling to get to valve but am just about able to. In the FAQ, (which has a helpful diagram now), it says

"During this phase it is imperative that water or air is allowed to escape from the heating system"

Now i'm assuming the 'phase' is the pumping of air into the expansion vessel. How do I make sure water or air can escape? I have left a bleed valve open on an upstairs radiator will this be OK? Also i've shut the valves on all 5 pipes going into/out of the boiler, should I open up the 2 for the heating system (ie cold in\hot out)?

The advice given so far has been invaluable along with the FAQs, so thank you all very much.