All radiators air lock when new stove back boiler is lit

Just got a new stove back boiler and it has been causing problems from day one. All radiators air lock a couple of hours after fire has been lit, then the gurgling starts which gets louder and louder and lasts throughout the night. Gurgling quite loud throughout whole system and an engine like noise coming from pipes/pump beside fire. Water flows from overflow pipe too. Also have a gas boiler and radiators are fine when this is in use. Plumber who installed it just shrugged his shoulder saying he doesn't know why this is happening !!!

Help any ideas, not too sure what to do next !!