Service manual

Hydronic Heating Boilers and
Domestic Water Heaters
20
INSTALLATION Continued
The following is a detailed explanation of Sidewall Venting
Without an External Power Vent Fan installation requirements.
Flue Outlet Piping
Venting Guidelines
If using this venting option, a sealed AL29-4C venting system
for flue products is required on all models of this appliance.
This venting system operates with a positive pressure in
the vent. The internal combustion air blowers generate this
positive pressure which operates the combustion process and
also exhausts the flue products from the building.
This vent system has specific vent material and installation
requirements. Only use listed sealed AL29-4C vent system
materials. Follow all installation requirements. See TABLE–B,
page 13 for proper pipe size for your unit. A list of sealed
AL29-4C flue pipe manufacturers is located on page 24.
Seal all vent joints and seams gas-tight.
Drain Tee Installation
A drain tee must be installed in the vent pipe to collect and
dispose of any condensate that may occur in the vent system.
The drain tee must be installed as the first fitting after the
horizontal ell on the top of the unit. Plastic drain tubing, sized
per the vent manufacturer’s instructions, shall be provided as
a drain line from the tee. The drain tubing must have a trap
provided by a 3" (7.6cm) diameter circular trap loop in the
drain tubing. Prime the trap loop by pouring a small quantity
of water into the drain hose before assembly to the vent. Secure
the trap loop in position with nylon wire ties. Use caution not to
collapse or restrict the condensate drain line with the nylon wire
ties. The condensate drain must be routed to a suitable drain
for disposal of condensate that may occur in the direct vent
system. Refer to the condensate drain installation instructions
as supplied by the manufacturer of the vent material.
Connect the flue vent directly to the flue outlet opening on
the top of unit. Make the connections from the unit vent to
the outside stack as direct as possible with no reduction in
diameter. Provide adequate clearance to combustibles for the
vent connector and firestop. Follow the vent manufacturer’s
instructions when installing sealed AL29-4C vents and
accessories, such as firestop spacers, vent connectors, thimbles,
caps, etc.
Provide adequate clearance to combustibles for the vent
connector and firestop.
When planning the venting system, avoid possible contact with
plumbing or electrical wiring inside walls, ceilings, and floors.
Locate the unit as close as possible to chimney or gas vent.
When a vent system is disconnected for any reason, the flue
must be reassembled and resealed according to the vent
manufacturer’s instructions.
The installed length of flue from the unit to the outside point
of termination must not exceed 50 equivalent feet (15.2m).
Subtract 5 feet (1.5m) of equivalent length for each 90° elbow.
Subtract 2.5 feet (0.7m) of equivalent length for each 45°
elbow.
 WARNING: Do not combine the flue from
this unit with the vent from any other appliance.
Do not combine flues from multiple appliances
into a common vent. The flue from this unit must
be a dedicated stack.
FIG. 22 Sidewall Vent