Rad Bleed or Drain Tap?

[BillW]

Hello
I'm investigating a noise on my CH system. One of my thoughts is to reduce the boiler water pressure by somewhere between 0.5 and 0.75 bar. I've a Worcester Bosch 37CDi condensing boiler situated in the garage. To reduce the system pressure|I was just going to bleed a radiator but I notice in the boiler manual that there is a drain tap situated behind the boiler control panel. This drain tap is only mentioned in the manual's "Inspection & Service/Replacement of Parts" section.So:
1 - Will this drain tap allow me to reduce the pressure while watching the boiler's pressure gauge, saving me from having to stop/start a rad bleed and going to and fro from the garage or having to recharge the system?
2 - As this drain tap's only mentioned in the service/parts chapter should I even be touching it at all?
3 - Which is more likely to reintroduce more air - drain tap or rad bleed?
Cheers
BillW

 

[Billy Bob Bob]

Hello
I'm investigating a noise on my CH system. One of my thoughts is to reduce the boiler water pressure by somewhere between 0.5 and 0.75 bar. I've a Worcester Bosch 37CDi condensing boiler situated in the garage. To reduce the system pressure|I was just going to bleed a radiator but I notice in the boiler manual that there is a drain tap situated behind the boiler control panel. This drain tap is only mentioned in the manual's "Inspection & Service/Replacement of Parts" section.So:
1 - Will this drain tap allow me to reduce the pressure while watching the boiler's pressure gauge, saving me from having to stop/start a rad bleed and going to and fro from the garage or having to recharge the system?
2 - As this drain tap's only mentioned in the service/parts chapter should I even be touching it at all?
3 - Which is more likely to reintroduce more air - drain tap or rad bleed?
Cheers
BillW

dont try that!!!!!!!!! what presure do you have at the moment when the boilers cool

 

[oldplumber]

best to tell the world your symptons in detail so someone can try giving a sensible diagnosis rather than trying out your own diagnosis/solution based on ??

 

[derrybongo]

It would be a lot simpler to just go round all the radiators to check for any air locks and by doing that you may have dropped the pressure slightly anyway. Also come down in small steps and leave for a while to see if the noise disappears.

 

[BillW]

Thanks for the prompt replies!
(Old Plumber - you've also kindly replied about 45 minutes ago to a previous posting of mine "CH NOISE" which relates to my ongoing problem).
All I'm doing is looking at the boiler pressure as one possible cause of the noise (amongst others). The pressure when cool is currently around 1.75 ish and wondered if it would be better reduced to around 1 bar? Interestingly the manual, under "Filling the System, refers to "refill the system up to 1 bar........." and under "Water Treatment" "Re-pressurise if necessary to 1 bar............" so I was wondering if 1 bar was some sort of preferred pressure?
Gas man & Derry bongo - guess I'll just do a rad bleed then!
Ta
BillW

 

[GreenArmy]

Did Jambo fit your boiler and rad valves?

 

[BillW]

Eh? Who's Jambo?

 

[andrewcplatt]

Soooo dramatic.