ideal vogue excess air problem

[PlumbBobBob]

I have a customer who had a vogue fitted in march, not by me, which is suffering from excess air in the system every morning. the only thing that has been changed on the system, microbore on manifold, is doing away with a radiator because they now have a log burner in the lounge. can anyone think why this is happening every morning? the boiler comes on as normal then clunks and bangs and shuts off, cust then runs the auto venting on the menu and the boiler runs as normal.

could it be because there are two dead legs on the manifold?

 

[jtsplumbing]

Possible can you cap off unused tapping's at manifold ? is he on OV or sealed system ?

 

[PlumbBobBob]

yes I can cap off at the manifold. it's a sealed system was ov before.

 

[jtsplumbing]

Got to start from somewhere, not losing any pressure ?

 

[PlumbBobBob]

no, no pressure drop at all

thinking on it a bit more, could be one or more rad valves they are all original 15-20 years old

 

[jtsplumbing]

Old system could be pulling air from anywere

 

[PlumbBobBob]

Old system could be pulling air from anywere

true, just have to work through eliminating as I go

 

[Roger Welton]

Not flushed and no inhibitor.

 

[jtsplumbing]

Is system in copper or plastic ?? if plastic may NOT be barrier pipe

 

[TFGplumbing]

Plot twist - its not air its hydrogen sulphide

 

[jtsplumbing]

Quite possible, maybe didn't flush system when they replaced boiler

 

[TFGplumbing]

I'am just throwing some Ideas around as I have a very similar problem on a job, I think pin hole on the return or radiators have a corrosion problem.

 

[spanner]

Plot twist - its not air its hydrogen sulphide

Must remember that with barrier pipe.!!! As I need never used it before in wet system normality copper unless hot or cold water . What was the other plastic pipe unsuitable for CH?
Sorry to interrupt!!!!!

 

[Billy Bob Bob]

Plot twist - its not air its hydrogen sulphide

quite likely ,if there is air in the rads steve,try setting it on fire when you bleed it

 

[PlumbBobBob]

system is all copper microbore on a huge old manifold. don't know if it was flushed or not, but inhibitor is in as I put it in when I changed a couple of rads for towel rads. going back on Monday to attempt to get to the bottom of it.

 

[PlumbBobBob]

right then got to the bottom of in the end. it was one of the rad valves leaking from the top added to which the microbore had a Yorkshire converter up to 15mm for the valve which was hardly soldered at all, surprised it held the pressure back tbh. all good now.

 

[TFGplumbing]

right then got to the bottom of in the end. it was one of the rad valves leaking from the top added to which the microbore had a Yorkshire converter up to 15mm for the valve which was hardly soldered at all, surprised it held the pressure back tbh. all good now.

This is what i'am going to investigate on my next job, got a similar problem with a heatslave.

Did the system lose pressure with you steve?

 

[PlumbBobBob]

no it didn't lose pressure which was so strange

 

[PlumbBobBob]

the thing was I had to remove the plastic cap to find the leak it was only seeping out but enough to let air in