Combi boiler too much pressure

[bc123456bc]

Hello as the title says my boiler runs for 10 mins and within those 10 mins the pressure on the gauge is up to 4 bar !! I know I shouldnt have but I took cover off myself for a look. First thing I done was open the PRV and no water came out and no drop in pressure!? I disconnected the pipe from the pump (flexi one) that goes to PRV and Expansion vessel and no water escaped ?? Surely this should release water and drop pressure? Do I have a blockage somewhere? thanks
Bob

 

[wiggikins]

Turn your boiler off and get somebody who knows what they are doing to take a look ............before you damage yourself and/or your boiler

 

[kevplumb]

Do I have a blockage somewhere? thanks

aye between your ears

turn it off before it turns you off

and take wiggikins advice

 

[bc123456bc]

Boiler has been off for 2 days and cover is back on. Surely though somebody must hav an idea why its over prsurising and when PLV is opened nothing comes out ?

 

[bengasman]

yes, lots of us have a really good idea what the problem is.

leave boiler off.

get an rgi to fix it, as you are likely to get seriously hurt when you turn the boiler on.
there is a blockage in the boiler due to poor installation and/or poor maintenance. the 4 bar in stead of 3 bar may even indicate the prv is faulty which means if your boiler gets too hot, it will not leak, but explode

you also have taken off a connection at a place where the water is the hottest.
if and when this lets go, it will probably be when the temperature and pressure are the highest.

if you get that in the face, your pulling days will be over, unless you are a hard-core goth

 

[clivvee]

ok,,,,,,this is it....if the guage is running high on central heating and reads ok on hw only... also the prv- pressure relief valve might be open when pressure hi..>>.the filter strainer is blocked on return pipe to boiler..on mine the prv was dripping ..obviously blockage in system..when boiler cold the pressure will show low and u will be topping up..?
looks like large brass joint offset large nut...dont undo it......drain system..cen heating..then undo nut and u wiil find the filter..u can clean with toothbrush and a bit of brillo pad..when u can see through it side on its clean ..reinstall...use bit rtv on end cap joint...refill systemm,,,,,sorted..
refill boiler to approx 1 bar only..
obviously call plumber if u are not up to or unqualified.
u will need bleed rads after filling system..do this before switching boiler on
if boiler drops slight pressure-- bleed and fill system until 1 bar on guage.u may here a hissing noise..this is auto vent on boiler and will selfbleed boiler only....
hope it works for u..prob best replace prv at time of cleaning/replacing the strainer
if u are seeing hi pressure and the relief valve is not blowing off.usual copper pipe outside wall adjacent boiler (u will c steam!!)..turn off and call a plumber/heating eng...

 

[ChrisOxford]

if you get that in the face, your pulling days will be over, unless you are a hard-core goth