gas water heater

[hammers4spanner]

Got a call out to this right at end of the day ,
gas powered water heater hot water supply pressure to taps has dropped off , its a tank fed water heater with open vent and pumped circulation . I can hear the air going through pump and spluttering through pipes to taps .When i run taps on one side of class the pressure is fine goto other side and its a bit of an issue al in all its 7 hot water draw offs either side of class so in total 14 taps . i know the pressure was fine prior as have done the odd leak here there in class .
Thinking to try draw air lock out through pump or would wet vac be man enough???
Any other suggestions welcome

 

[Dotty]

Reverse your secondary return pump.

 

[hammers4spanner]

that should pump it out through vent i presume?

 

[Dotty]

No, you're reversing the secondary flow but any trapped air should be pushed up the vent.