Does this pipe layout look correct?

[holty]

an apprentice working for someone else told me his boss fits aav,s on both the return and flow. then i pointed out that an aav on the return will be under negative pressure hence drawing in air. and thats being taught by a so called corgi proffesional.

 

[Onetap]

then i pointed out that an aav on the return will be under negative pressure hence drawing in air

Not necessarily, it depends on the layout of the system & the static pressure available.

You shouldn't need any AAVs on a heating system after all the air has been initially vented. The AAVs' isolating valves/caps should be shut after a week or so because they can stick open.

 

[mk2phil]

Nige - is it definately a Warix then..?