Baxi not holding pressure

howdoyoudo2103

Hi all, Baxi boiler, if I repressurise using the filling loop, gauge rises to 1.5bar but then instantly starts dropping and water starts flowing from overflow off header tank, gauge eventually drops back to almost zero, any ideas?

Lenar3556

A sealed system (which would typically be fitted with a filling loop and charged to 1.5bar) wouldn’t have a header tank. In commercial applications there may be a pump set incorporating a tank, but that seems unlikely in this case.

Putting 1.5 bar into on open vented system would back feed into the header tank and eventually overflow - the question is what type of system you have and why is there both a filling loop and header tank - typically there would be one or the other.

Some photos may help explain.

howdoyoudo2103

This is what has me baffled, there’s no pressure vessel but all along I had no problem topping up the pressure and getting the gauge on the baxi to 1.5 bar, didn’t even think about header tank until this time around when it overflowed

Wearb

Maybe the overflow is from the domestic water tank?

howdoyoudo2103

No definitely from a header tank, the way house was plumbed originally anything is possible