Venting requirement for Bosch AQ4 Powervent kit

The Bosch AQ4 Powervent Kit with built-in freeze protection is designed for the Bosch Therm 520HN (Hydro Ignition) and 520PN (Pilot) tankless water heaters. This accessory allows the Bosch 520HN and 520PN tankless heaters to vent horizontally out the sidewall of the home.  The AQ4 does require power to operate and operates on 120V and comes with a 3' cord to plug into the outlet.  

  The AQ4 is a power vent kit and will allow a horizontal vent run of up to 25 feet with one elbow (subtract 5 feet for every elbow). This kit includes the power vent motor.  There is also a vent hood with damper that gets mounted on the outside of the home and this built in flapper prevents the cold air from coming in when the heater is not in use.  Please make sure to refer to the installation manual and that the hood is properly installed so that the flapper stays closed all the way when not in use.  

The AQ4 powervent kit comes with a 5" to 4" reducer. This reducer fits right on top of the heater and then you would use 4" type B, C or stainless steel AL29-4C venting (not included) to go to the powervent motor.  There is a minimum of 2 feet of straight pipe required between the reducer and the blower motor.  Any venting (if needed) "after" the powervent motor must be 4" sealed stainless steel AL29-4C.  The Blower motor should be placed right at the opening where the termination hood with damper is to be installed on the sidewall of the home.

The AQ4 powervent kit is activated by a flow switch and gets attached to the cold water pipe on the right side of the unit just before it goes into the heat exchanger. 

The blower motor for the AQ4 has a new design and includes a delay setting that goes from #1 - #5 and this lets the installer set the blower motor so that when it senses flow it can be delayed for 1 - 5 seconds before the blower comes on.  This will help to ensure the pilot and burners light without getting sucked out by the blower motor. 

There is also a built in safety spill switch that gets attached to the tankless water heater and this will detect high temperatures from any flue gases in the case the blower motor does not activate and will shut the unit completely down.

$$ Special Sale on Bosch Vent Kits $$

We are pleased to announce a *very* special sale on all Bosch vertical and side-wall vent kits due to our large overstock position! We absolutely guarantee the lowest pricing on our vent kits and we will be happy to beat our competitor's pricing on any of the Bosch vent kits listed below!

We sell the AQ3ES Side-wall vent kit for the Bosch 940ES, 830ES, Evolution 500, 2700ES and 2400ES tankless water heaters. This is a 3" Category III stainless steel vent kit that contains all of the 3" venting parts needed to exhaust one of the above-mentioned tankless water heaters by going up and directly out the side wall.

We also carry our own AQ3ESPLUS kit which adds a set of WebStone 44443PR Isolation Valves and an 18" Auto-reset GFCI to the standard AQ3ES horizontal vent kit.

For those customers who are venting out a side wall that is perpendicular to the wall on which the Bosch tankless water heater is installed, we do offer the ESHCK-FULL-KIT -- a 3" Category III stainless steel concentric vent kit. This kit comes with the ESHCK concentric piece along with a 3" x 90 degree elbow, a 3" x 3' pipe and a 3" termination tee.

We carry the ES VVT through-the-roof vent kit for the Bosch 940ES, 830ES, Evolution 500, 2700ES and 2400ES tankless water heaters. This vertical vent kit contains all of the 3" Category III stainless steel venting parts needed to vent up through the roof except for the straight pipe, which is sold separately in pieces ranging in length from 6" up to 5'.

We also are the exclusive distributor for the ES VVT STEEP vent kit. In this kit we swap out the standard Adjustable Roof Flashing contained in the ESVVT vent kit for a Steep Roof Flashing at no extra charge.

We are the exclusive distributor for the AQ5EF side-wall vent kit for the Bosch 660EF tankless water heaters. This kit contains the true 2SVSWB03 Adaptor which you can only get through our company. The AQ5EF horizontal vent kit will also work with the Noritz NR-66 tankless water heater.

Looking to vent your Bosch 660EF or Noritz NR-66 through the roof? Just add the 2SVSWB03 Adaptor to either the ESVVT or ESVVT-STEEP vent kit!

Lastly, we carry the H/P VVT vertical vent kit for the Bosch 520PN, 520HN, 1600P, 1600H, GWH 425PN and certain 425HN tankless water heaters. (We also sell the AQ4 side-wall power vent kit for these same six heaters, but we are not overstocked on this part.)

The following vent kits are always in stock, but are not a part of our special sale pricing: the AQOK, BTOK and PTOK Bosch Outdoor Vent Kits and the Bosch Therm Concentric Vent Kit (196016). This latter concentric vent kit is made of PVC and is used only for the Bosch condensing tankless water heaters that are efficient enough to lower the exhaust temperature to a point where it is safe to vent through PVC.