Turbomax Expansion Vessel - DIYable?

[gaswizzard]

Bloody hell repressure it properly first an gas wizard it doesnt Mean the ev is goosed if water from the shraeder! We get it often on the vaillants ,u refill em an there fine. Do probably 2000 vaillants a year over 26 years an changed 5 vessels!!

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• Bunnyman
• 26 Mar 2010
• 499

So tell me , how does the water discharge from the scrader if the diaphragm is not split? , or are you saying these vaillant vessels are special?

As I said on another post , the vaillant vessels along with most other manu are undersized , especially when referring to the 35/37 kw models , these vessels are sized for 1 bar system pressure , plenty properties out there requiring 1.5 bar min pressure (3 floors) , those vessels are not sized for these situations.

 

[gaswizzard]

.
I then pressed the pin in the ev's shrader valve, and jets of water are shooting out. Loads of it.

Think it may be goosed bunny man.

Sure you can repressurize if the diaphragm has holed/split but how long will this last? , years ago we used to use expansion tanks which had no diaphragm at all , what happened here is the air charge got depleted pretty quickly due to the system water absorbing the air , problem with these systems was the steel panel rads would pin hole after a while.

 

[Bunnyman]

If its spraying loads out then it's knackered but if it's just half a pint or so that's usually just condensation that's formed due to heat transfer especially if it's bin empty for ages, the old vc with the small tank on the lhs could easily leak a pint . an the sine an vcw used to leak between the diaphram an the seam, if the tank was completely empty an when u refilled with air the diaphram would seal back into the seam no problem

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• Bunnyman
• 26 Mar 2010
• 499

 

[youdontwanttodoitlikethat]

Didn't mean to start a debate. Thanks for the info though.

If it helps, the water coming out of ev was discoloured, and smells of corrosion inhibitor. Also, can get loads out of valve. So, I'm thinking it's not condensation.

As no one encouraged me to do diy replacement., it's going to be a seperate ev next to boiler.

 

[gaswizzard]

Didn't mean to start a debate. Thanks for the info though.

You didn't , but either way hey ho.

 

[Agile]

I think what agile is refering to is the fact that it is sometimes still possible to repressurise the vessel against the system (a bit like using a half empty rad to provide expansion space in a emergency)

Matt

No, I was not actually meaning that.

I let the system water pressure drive any water out of the valve. If that ceases then there is no hole in the diaphragm.

Then I depressure the system and add air pressure to 0.9 Bar. If it holds that then the diaphragm is not holed and I reassemble the boiler and in most cases its fine for many years.

Tony

 

[bell824]

As far as i am concerned a fully depressurised vessel will leak water from the schreader dure to condensation, only after topping it up and presure testing the diaphragm side (does it hold pressure????) can you tell if the diaphragm has burst, most form's of air carry moisture and most diaphragms are permiable so therefor it is not unusual to find water on the air side of an expanssion vessel.

 

[gaswizzard]

Whether these vessels use a bladder or not any water collected due to moisture within the air will sink to the bottom of bladder/diaphragm , whether a vaillant or otherwise i've never had water showing at scrader when vessel not split/holed , and yes i've also worked on thousands of boilers Vaillant or otherwise. , cut the thing up and it will be quite apparent.

 

[Bunnyman]

we agree to disagree on this then wizard