Vaillant turboMax lockout

[Lorcan64]

My boiler, which is about 5 years old and regularly serviced has decided to lock out on a fairly regular basis now. The last time it happened, this morning and twice over the weekend. It had done it about a week before that too. Central heating was working when I went to bed last night. This morning lock out. So as expected no CH. Water pressure needle not registering anything. I put water into the system, up to 1 bar and fired it up and away we went. It works. I had noticed some weeks ago that when the CH was on the pressure shot in to the red. Today topped it up let it run for a bit then turned CH off. Pressure gauage dropped just below 1 bar. Topped it up to 1 again and let it rest. It maintained 1 for about 15 mins. I then activated CH. It fired up. I then shut it off. Pressure guage appears to be holding at 1. My suspicion is that I have a leak somewhere in the pipework. All rads appear dry and no staining on the ceilings. Might therefore be under the ground floor. I have noticed staining on the wall where the relief valve pipe protrudes outside.
Suggestions most welcome.

 

[linkyplumb]

It sounds as though your expansion vessel is shot or needs recharging.

Check outside where the pressure relief valve pipework is, to see if it is wet or dripping.

 

[Lorcan64]

There have been signs of the expansion pipe discharging but seemed dry this morning

 

[Agile]

Tie a bag or bottle over the vent pipe!

Tony

 

[Whitespirit66]

If you look down the back of your boiler from above, you can see the red expansion vessel. There is a short pipe sticking out of the vessel (arrowed in the image below) with a Schrader valve (same as car tyre) on the end. Unscrew the red cap, and quickly press the pin inside the valve. If water comes out, it's likely the vessel is shot.

Untitled

• Whitespirit66
• 17 Apr 2012
• 3

If it's shot, it may be cheaper to leave the old expansion vessel in place, and fit an external one. Removing the old one requires taking the boiler off the wall.

If no water comes out, it may need repressurising as in here -

//www.diynot.com/forums/viewtopic.php?t=37170

 

[Lorcan64]

Excellent. It looks like it was a bicycle pump job that seems to have resolved the issue. I don't remember seeing that in the manual. Got an excellent 'plumber/engineer' recommended by an equally excellent plumber/engineer to sort it.

Thanks all for your advice. It is appreciated

 

[simond]

The bicycle pump solution is only a temporary fix. The air and water are kept separate by a rubber bag. Once

If the air charge has gone, it's leaked out. And that is where the air out of your bicycle pump is going too.

You can sometimes get the exp vessel out of a turboMAX without removing the boiler, it depends on the distance above the boiler and the way the flue has been installed.

NB: If you have a turboMAX, it's going to be at least 7 yrs old, not 5.

 

[Bunnyman]

They go down in normal use simond an need refilling regularly. And just because they got water in don't mean it's shot! When the. Vessels get pumped up the diaphram makes a water tight seal inside the. Vessel lip. When it they run empty the diaphram gets slack an water can pass

 

[Agile]

When the air valve is at the top like this its best to let ALL the air out as there can still be some water at the bottom.

As Bunny says just because there is some water coming out it does not mean that it will not work ok when the air is correctly repressurised.

Tony

 

[Lorcan64]

Thanks again guys. Don't fancy more expense. I have noticed that the pressure has dropped when cold very very slightly. I had topped it to 1 but after a few days it's at I would say 0.95. As I said very slight drop