Expansion tank connected to pressure release valve

[TeeDee]

As they would say on the radio, long time listener, first time caller.

I'm installing a Peerless gas boiler (MI-04). It shows in the manual that I can hook up an air elimination device on the same pipe as the pressure release valve. Can I also connect the expansion tank to this pipe? I ask because this is the way is was installed in the house it was removed from. A 1 inch pipe that comes up for the top of the boiler to a T. The horizontal pipe off that T is the pressure release valve. The vertical pipe that continues extends 20 inches to another T. The pipe to the right of the T is the air vent and the pipe to the left of the T is the expansion tank. Is this okay? Thanks in advance. I will add photos if it helps...and if I can figure out how..

 

[Terry]

Please add the photos. 800 pixels or less.

The PRV needs to come off the main piping for the unit and so does the expansion tank. You need to make sure these are on the pressure side.

 

[Sponsor]

 

[Tom Sawyer]

Yes you can as long as there are no valves between the expansion tank, the relief valve and the boiler itself

 

[BadgerBoilerMN]

Careful here. The pressure relief valve (PRV) on any boiler and it's location are specified by the manufacturer. In general the relief valve is installed off a direct connection to the top of the boiler and nothing can be between the PRV and the boiler save pipe.
There may be a tee off the top for an expansion tank but the boiler does not care where the expansion tank is, only the circulator worried about such things.