loss of pressure on combi boiler

[aztec12]

Hi not used this before so please bare with me... I have a worcester Bosch 230 combi - boiler and it keeps losing pressure suddenly. The reset button pops up when this happens. To get it going again I first refill the system by opening the loop and then press the reset button. It loses pressure within 30 to 45 minutes. I have checked for leaks but nothing visable can be seen. Not sure what else I could do...Any suggestions wold be greatly appreciated and potentially life saving in this weather

 

[glasgowgas]

any leaks from here??



View media item 17623

 

[aztec12]

Hi, yes , its a drop at a time and I can see clearly that it has been dripping for some time as there is a large wet patch on the wall which is semi frozen. Hope that makes sense

thanks in advance

 

[glasgowgas]

expansion vessel may need re charging or replacing. see FAQS at top of page

or PRV is passing

whats boiler pressure when cold ( should be about 1.2 bar)

what does it rise to with heating on? (if it rises to 3 bar, PRV will lift and dump excess pressure, therefore when htg has stopped and cools down it will be less than when you started at 1.2 bar)

also make sure the filling loop is disconnected

 

[aztec12]

Ok.... What is prv?
The pressure gauge shows a reading of 0 unless I refill using the loop. The loop has a stop tap not screw type if that helps and is fixed so not easily removable.

If I set the pressure to 1.0 when the heating is switched on it would rise to 1.5 gradually and then stop. Hope this helps

 

[glasgowgas]

PRV = Pressure Reducing Valve

it sounds like it is passing and requires replacing, it should lift when boiler pressure rises to high (3bar)

if gauge is only going to 1.5 (which is exactly what it should do), then PRV is Donald Ducked

 

[aztec12]

ok thanks. It has Im sure rose to a very high pressure a few times before (possibly 2.5 - 3) If this is the case what would that mean?

Is the pvr change an expesive job?

 

[glasgowgas]

as previously stated check FAQS at top of page concerning expansion vessel recharging

PRV replacement is outlined in your boilers manufacturers instructions, easilly diyable, as is exp vessel re charging

 

[aztec12]

thats great.. Thank you for all you help

 

[aztec12]

Ive tried recharging th expansion vessel and no luck... Looks like it may be the PRV.... any one know where to get an instruction manual for the Worcester Bosch 230?

 

[aztec12]

also one last thing is that a managed just now to find a couple of pages related to this boiler and it sos a diagram of the pipes that go in/out of the boiler (underneath). Should they all be switched to on? The central heating return on the diagram indicates the off position. Any help would be greatley appreciated