Sealed Heating System - Pressure increasing?

Retail Mngr

Hi

So Scenario....

Noticed PRV in boiler housing blowing off from time to time.

Following it for a couple of weeks now and have noticed pressure increases over the space of a week from 1bar cold to nearly 4bar hot and then the PRV blows off.

Releasing pressure back down to 1bar cold helps for a few days but then it climbs again.

Am 99% sure the filling loop is closed.

The pressure vessel is sound and still has pressure on the dry side.

So Questions...

Wheres the water coming from?
Is it possible for the filling loop tap to be leaking ever so slightly?
is it possible to have a leak inside the cylinder from the secondary into the primary system?
Is there a way of checking/testing this?
Any other comments or suggestions?

Thanks

Paul

Billy Bunting

The filling loop should be disconnected once the system is pressurised, it could let bye.

scudo2

Also check that pressure vessel / red tank has full charge of air at 1.25 bar. And that its light and hollow sound if you gently tap it with a spanner.

Sparkpea

its not an automatic topup system on it is there thats failing at the set pressure?

otherwise i'd go with billys advice and make sure the inlet is disconnected...