pressure up to 3 on gas heating system

shaneomc

hi
last week the pressure was down to 0 when i looked at the guage in the hot press .The gauge has a lock nut and threaded screw on the top (what is that for) and a valve under it to let the water in .Ihad adjusted the threaded screw to see if that made any diff but none so i let some water in an brought the pressure up to 2 . i left it alone for about an hour or so snd the pressure was down near 1 but saw there was a small leak on a joint on the pipe at the gauge joint , thightened it up an no leak . but now the pressure is up at 3 , i let out some water from a rad , but it keeps rising to 3 when heat is on for a while and pipe from boiler to out side is dripping . what damage can high pressure do to a system ? cant be good for pipe joints ? iv read it shoul be only around 1.5 -2 bar how can i fix this

mullingar

You have a pressure relief valve in your system designed to release any pressure >3bars. From experience, these never 100% reseal if they are a few years old (sludge etc) 1.0-1.5bars is ideal


I'd check your expansion vessel (The big red bubble thing)

There should be 1.0bars of pressure in it when its disconnected.
DO NOT TEST IT WHEN HEATING IS CONNECTED AND PRESSURISED

It usually has a car tyre valve so you can bring it to a garage to test if you dont have a pressure guage.

If its at zero, pressurise is to 1.0bar. Leave it for a few hours (if possible) and re-measure. It should still be at 1.0bar. If not, replace it as its faulty.

shaneomc

thanks mullingar, my system dosent have the expansion vessel . its a sealed system the guage is on the mains pipe up to the one tank in the attic. i think im gonna bleed one of the rads till pressure goes down to 1 an see what happens

Buford T Justice

If you're system is sealed, then it must have an expansion vessel fitted, otherwise its dangerous. Check and see is there one in you're boiler.