Gas Boiler Exhaust

This pipe sits at about waist height on the side of a home. It gets very hot and the exhaust gas is very hot. (obviously) I rarely see a boiler around here and only see wall vents for gas fireplaces. Common sense tells me this is not safe. but how should it be routed and terminated/labeled?

The answer depends on the manufacturer and model of the boiler.

Yes, installation instructions rule.

You’ll also want to check about clearances to operable windows, doors etc.

It is installed per the manufacturer. Thanks guys.