combi expansion vessel test

[riduna]

Hi There, I recently had to have an engineer out to cure a small leak on my wallstar boiler which is just out of warranty, oil fired. the leak was sorted simply, a failed rubber seal on a connection. Casting his expert eye over the boiler we were informed that the expansion vessel was faulty and must be renewed. We pointer out that the system had given us no trouble, but he insisted that he was correct and that the diapagmn was damaged and it was not able to hold pressure, we reluctantly agreed to the change and he fitted a new part. I am a retired clerk of works and am quite savvie on most aspects of allied trades. combi condensing boilers are something new to me, I retained the old unit and the nxt day checked it over. I found that the vessel showed no signs of pressure loss and there was no sign of water at the shrader valve, I have since had a long telephone conversation with the engineer who stands by his diagnosis and tells me that there is no way of telling that the vessel had failed one way or the other, and that replacing it was required. I reffited the original vessel and there is no increase in pressure or loss of water, it has been running for now fo 10 days satisfactory. Are there any other tests that could be carried out that would put beyond doubt the situation. Have two oap's been had?.

Regards to all, Riduna

 

[PlumbBobBob]

if as he said there is no way of telling that the vessel had failed or not how did he know? must be psychic

 

[dontknowitall]

Sounds like it has to be pistols at dawn, Riduna.

Easy way to test (although not very scientific) is to press the valve momentarily to see if air comes out. If it does it means it's not full of water so should be fine. Obviously there will be exceptions to the rule but in 99% of cases that's all that is needed to know.

 

[dontknowitall]

Was he OFTEC qualified?

 

[riduna]

Hello mate, thanks for your reply. I do not know what quallifications he has but I will endevour to find out, thanks for your reply.

 

[riduna]

Hello mate, thanks for your reply, I have done as you say and all is ok. The pressure on the vessel is holding steady at 1bar.
and there is no sign of water from the shrader valve and there is no increase of water pressure on the system.
All seems ok, sadly. many thanks for taking time to reply.

 

[Destroyer2813]

The easy way to test the vessel is get a tyre pressure gauge and test the internal pressure see what it reads and then compare that to the manufactures instructions

 

[quality]

Sounds like it has to be pistols at dawn, Riduna.

Easy way to test (although not very scientific) is to press the valve momentarily to see if air comes out. If it does it means it's not full of water so should be fine. Obviously there will be exceptions to the rule but in 99% of cases that's all that is needed to know.

That s the way to do it

 

[riduna]

Hi There, thanks for your reply, psychic not the word that springs to mind with me. I should of realized when he said he had a spare one!! so have I now. Do'nt get old there is no future in it.
Many thanks for taking the trouble to reply about our problem.

 

[riduna]

Thanks for that, have done that and the pressure holds at 1 bar as the handbook spec; thanks for your advice.

 

[riduna]

Something like that . I will star off with the pen,though. thanks. Riduna

 

[kimbo]

You will need to represurise it every so often,you will have to drop the system pressure to zero and check the expansion vesel pressure, you may need to top it up to 1 bar with a footpump, its done at every service.

 

[riduna]

Hi Kimbo, Thanks for your reply. I have checked the pressure and it holds at 1bar ok.
I was told by the engineer that the diaphagmn was leaking as he could not pressurise it.
was'nt we lucky that he had a spare one!
every test seems to show that it is faultless, its now been working for 11 days without showing any problems, system pressure ok, as a result no PRV escape, and no water from shrader valve.
Thanks for you taking the time to help, many thanks. riduna