Condensing gas combi boiler Common vented

bob eck

Are there any condensing gas combi boilers wall hung that can be common vented together?

JakeCK

No.

Noel

In larger sizes, this is available. https://www.bosch-climate.us/files/201309192156100.6720646836_GB162_Flue_Cascade_Kit_Installation_Instructions_en-fr_08.2013.pdf

JakeCK

I stand corrected.

I like the first thing listed on the second page:
" To be installed by a heating engineer only." I wonder why.

Henry

In our gas code, only the same make, model and capacity, plus each unit must have a factory installed backdraft prevention device can be combined vented.
Most NA manufacturers have followed our recommendations.

Solid_Fuel_Man

The scary thing with positive pressures common venting is that is a unit (which is off) has a poor seal on the backdraft damper then combustion gasses reverse flow through the appliance. No good will come of that.

GroundUp

I'm not a Navien guy so I can't say for sure, but I have seen a whole lot of Navien units piped to a common vent when cascaded.