Worcester 28CDi pressure problem

[baz995]

Hi all

stumbled on this great site whilst trying to find a solution to my following problem:

I noticed a few weeks ago that my pressure gauge was reading 3bar so i got the manual out and drained off the system until it read 1 bar then re-filled to just below 1.5 bar. All seemed well. A few days later i noticed that the hall rad was cold despite heating being on, i checked all the others and all my rads were cold to the touch. Checking hte boiler again revealed that the pressure gauge was reading zero. So i re-filled the system again to 1.5 bar and checked the rads for air and two needed bleeding. All seemed well again but tonight the gauge is showing 3 bar again??? any other experience of this or any ideas would be great please

many thanks in advance

Baz

 

[nickso]

check the FAQ's for expansion vessel issues. if its not that then the plate heat exchabger could be passing.

 

[baz995]

many thanks

i did have a look prior to posting but was 100% what i was looking for, i am going to try to re-pressurize the thing. I have also noticed water dripping from the drain pipe on the outside of the house if that helps?

 

[nickso]

the water dripping outside just tells you that the PRV has let the excess pressure out as it should. it still could be the vessel or the PHE. im willing to bet your PRV will not seal properly now either.

try to repressurise the vessel and see how it goes.

 

[twgas]

I have also noticed water dripping from the drain pipe on the outside of the house if that helps?

It may help diagnose the fault on your boiler, but it won't help the boiler work properly.

 

[baz995]

hi again

well i checked the expansion vessel and it is reading 12 psi? is this sufficient? i notice the manual says it 7 psi from the factory

 

[nickso]

did you do it properly with a drain or the PRV open?

anyone know what 12psi is in bar? i only do bar

 

[gassafeengineer]

if your PRV is dripping then there is dirt on the seating and this should be replaced as it will cause your pressure to drop. The Expansion Vessel should contain about.75-1 bar of pressure in its internal bladder u should check this by first pushing in the pin on the schrader valve until all air pressure has gone if u notice water then the expansion vesel is knakerd if no water you should drain system then pressurise expansion vessel change PRV and fill system not forgetting to introduce a chemical inhibitor to the system to protect it.


please send cheques or cash

thanks

 

[kevplumb]

did you do it properly with a drain or the PRV open?

anyone know what 12psi is in bar? i only do bar

give or take 1 bar

 

[baz995]

12 psi is 0.82 bar, thanks for all the advice will have another look before the weekend

 

[baz995]

sorry forgot to say that i have inhibitor but i am uncertain how to introduce into the system?

 

[gassafeengineer]

hard to do on a pressurised system without a pump to do it you can buy it in a silicone tube which can be squeezed in at a radiator

 

[baz995]

many thanks

 

[nickso]

hard to do on a pressurised system without a pump to do it you can buy it in a silicone tube which can be squeezed in at a radiator

messy.

drain a small rad. rad tail into top connnection. short bit of hose onto tail and other end on a funnel. pour it in. 10 minutes.

 

[sooey]

did you do it properly with a drain or the PRV open?

anyone know what 12psi is in bar? i only do bar

14.7 psi is one atmosphere at sea level= 1 bar