water pressure on combi boiler

[mbed]

I HAVE A 7 YR OLD COMBI BOILER ARISTON 27GENUS+.SINCE HAVING
A NEW 4 LITRE EXPANSION VESSEL FITTED 4 WEEKS AGO. I HAVE TO
CONTINUALLY KEEP AN EYE ON THE PRESSURE GAUGE AND FILL UP
WHEN IT DROPS NEAR 0.5 BAR.THERE ARE NO SIGNS OF LEAKS OR AIR
IN RADIATORS AND THE OUTSIDE OVERFLOW IS DRY.HAS ANYONE
ANY IDEAS?

 

[glasgowgas]

expansion vessel is too small

should be at least an 8 litre one

fill ch system to 1.5 bar and run ch

what does pressure rise to?

 

[mbed]

THANKS FOR THAT BUT THE FITTER ONLY REPLACED WITH SAME SIZE
WHICH IS A 4 LITRE VESSEL;COULD IT BE FAULTY?

 

[glasgowgas]

according to the boiler MIs


0327 7 L. STANDARDISED EXPANSION VESSEL 65101719

its a 7 litre exp vessel

your fitter fitted the wrong one

 

[mbed]

THANKS:BUT THE REPLACEMENT VESSEL IS EXACTLY THE SAME SIZE
AS THE ORIGINAL THAT WAS FITTED.ENGINEER USED A FOOT PUMP
TO CHECK THE PRESSURE AND THE OLD ONE WOULD NOT HOLD AIR.
HENCE HE ORDERED A REPLACEMENT FROM ARISTON WHICH IS 4 LITRES
CAPACITY.

 

[glasgowgas]

fill ch system to 1.5 bar and run ch

what does pressure rise to?

 

[mbed]

THE SYSTEM THIS AM HAD SHUT DOWN DUE TO THE PRESSURE
DROPPING TO 0.5;I HARDLY SEEMED TO PUT MUCH WATER IN VIA
FILLING LOOP WHEN GAUGE WAS UP TO 3.2 BAR.STARTED SYSTEM UP
AND WATER IS RUNNING OUT THROUGH OVERFLOW:ALSO LET SOME
WATER OUT VIA RADIATOR THOUGH PRESSURE STILL ABOUT 3.0.LEFT
SYSTEM ON AS FREEZING COLD.COULD GAUGE BE FAULTY?

 

[glasgowgas]

not a faulty gauge, but a faulty expansion vessel its either dead/undersized/needs recharged
see FAQS ANDPLUMBING FIXES AND TIPS FOR EASY TO FOLLOW ADVICE