expansion tank pessure advice

[misterdubya]

Nickso has already explained, but the OP has blinkers on it seems.

Mr. W.

 

[joesoap1]

Its flat. That is unless your heating system is so big, you need a remote vessel fitting aswell, or your communication tube is blocked.

Mr. W.

Hi, How do you work that out, theres still 0.5 bar spare.I.ve only got 4 of 13 rads going at present.please explain FLAT. To me that means no air in?

Unless all rads are open you are not seeing the true full expansion of the system, most of the water in the syatem is still cold.
Also to get a 1 bar bressure increase with just 4 rads you have an expansion issue. Get all rads open at full temp and watch pressue and PRV discharge. Everything you have said sugests to me PRV discharge. I am no expert but this is how it seems to me.

Hi, Just turned all 13 rads on to max .will come backto you when they heat up.What expansion do you reckon from the 1.5 cold to max ?cheers

 

[misterdubya]

http://en.wikipedia.org/wiki/Expansion_tank

Here is a better description to read while the system heats up.
Keep your eye on the guage. Within 10 mins you may be near to 3 bar. If so, turn off.

Mr. W.

 

[joesoap1]

b*****r
misterdubya beat me to it.
But you will see we are both thinking along the same lines.

Hi, My most humble appologies.IT.S FLAT. Only reached 70 degrees and just touching 3 bar, ready to blow. Turned it down now. So you say I need to re-inflate exv to 1 bar. Never usually have boiler up full.I have done this before, years ago.

 

[misterdubya]

Have you pushed the shrader valve to ensure its flat and not knacked?
Out of curiosity, what is the make / model of your boiler?
The communication tube could be blocked, and in that case the vessel will be fine but it cannot work if its effectively 'removed' due to the blockage.

If its flat, follow the faq's. Remember to open the system up to the atmosphere.

Mr. W.

 

[joesoap1]

Have you pushed the shrader valve to ensure its flat and not knacked?

If its flat, follow the faq's. Remember to open the system up to the atmosphere.

Mr. W.

Hi, Just done that. Air coming out.This would not explain water loss would it? unless membrane was perforated.??cheers all. very much appreciated.Obviously never read your posts enough.

 

[Master of None]

Remember the water in the system is at 80degc at the moment. Use caution if you are going to do anything tonight. Ideally the system should be cold to put air into exp ves. At least you have found the real problem instead of trying to bodge it. Good luck. And remember because the PRV has operated at some point it may not have seated properly. this is not a part I would feel competent to change myself or indeed an exp ves. I would however feel putting air into exp ves a diy job.
PS I have only ever put air into my GFs Saunia Durval and you do not need to remove cover to do this.

 

[misterdubya]

Well, open up the system & re-pressurise to 1 bar. If your problems persist you may have a bigger problem (ie a Glowworm.)

Master of none has explained why the PRV has probably blown. That can be replaced at a later time but not until the route of the cause has been rectified.

Mr. W.

 

[joesoap1]

Well, open up the system & re-pressurise to 1 bar. If your problems persist you may have a bigger problem (ie a Glowworm.)

Mr. W.

Hi, Actually I was contemplating a new one next year.!7 years old Vokera.Just want to get winter through.Do you recommend Gloworm?

 

[Master of None]

If he does this at 80degc might this not damage membrain/bladder in exp ves when it cools as the effective pressure in exp ves will increase, as the system pressure drops.

 

[misterdubya]

Do you recommend Gloworm?

Not personally, but thats another topic as all RGI's have their reasons behind their choice of decent boilers.
You will see many discussions on this site about that.

Mr. W.

 

[joesoap1]

Do you recommend Gloworm?

Not personally, but thats another topic as all RGI's have their reasons behind their choice of decent boilers.
You will see many discussions on this site about that.

Mr. W.

Thanks , I will repressurise EXV tommorrow.And re-post result. Again,Thanks all

 

[misterdubya]

If he does this at 80degc might this not damage membrain/bladder in exp ves when it cools as the effective pressure in exp ves will increase, as the system pressure drops.

After 17 years who knows, but it can be fixed. I just wanna see it fixed as im off on the ciders in a bit. The missus is wanting to watch the s factor whatever that is.

Mr. W.

 

[misterdubya]

If he does this at 80degc might this not damage membrain/bladder in exp ves when it cools as the effective pressure in exp ves will increase, as the system pressure drops.

After 17 years who knows, but a new vessel can be put in 'remote' if circumstances allow. I just wanna see this pressure problem fixed as im off on the ciders in a bit. The missus is wanting to watch the s factor whatever that is.

Mr. W.

 

[Master of None]

Lucky you, its Strictly come dancing on my telly. So I have offered to cook dinner while having a few Strongbows interluded with the odd Magners.
oooo whats that burning smell........