ariston leak Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[achill]

i have an ariston system boiler with a small leak from the pressure relief valve, which over a few days allows the pressure to drop and thus the boiler locks out, then i have to top it back up has anyone got any ideas?

[htg engineer]

If pressure is not too high, then the pressure relief valve is passing.

Try opening pressure relief valve a few times, this can sometimes re-seat them.

If not, replace pressure relief valve - normally straight forward.

[achill]

when boiler on max the pressure reaches 3+bar then the leak becomes heavier

[achill]

pressure increases to above 3 bar then the pressure valve opens even more

[htg engineer]

Possibly a problem with the expansion vessel.

Look in this forum at posts by andy2010

[achill]

can it be topped up with air or do you know if it would need changing thanks for your help.

[htg engineer]

Can sometimes be re-pressurised to 1.0bar using a foot pump or similar.

Drain boiler so there's no pressure - lock open the pressure relief valve, Then pump to 1.0bar and refill system.

See if there's air at the valve on the expansion vessel. The valve looks like a one off a car or bike, If there's air then re-pressurising may work, if there's water then a new expansion vessel is required.