Install Instructions
54
9 Condensate disposal
Condensate drain
1. This boiler is a high effi ciency appliance that produces
condensate.
2. The side of the boiler has a 1/2 inch (12.7 mm) PVC
union for connection of a 1/2 inch (12.7 mm) PVC pipe
(FIG. 9-1).
3. Slope condensate tubing down and away from the boiler
into a drain or condensate neutralizing fi lter. Condensate
from the Knight XL will be slightly acidic (typically with
a pH from 3 to 5). Install a neutralizing fi lter if required
by local codes.
A Neutralizer Kit (FIG. 9-1) is available from the factory
(KIT3087 for Models 400 - 501 and KIT3046 for Models
601 - 801).
4. Install the 1/2 inch (12.7 mm) PVC tee assembly (shipped
with the unit) as shown in FIG. 9-1.
5. Leave the top of the 1/2 inch (12.7 mm) tee OPEN. This
is needed as a vacuum break.
6. Do not expose condensate line to freezing temperatures.
7. Use only plastic tubing or piping as a condensate drain
line (FIG. 9-1).
Use materials approved by the authority
having jurisdiction. In the absence of other
authority, PVC and CPVC pipe must comply
with ASTM D1785 or D2845. Cement and
primer must comply with ASME D2564 or
F493. For Canada use CSA or ULC certifi ed
PVC or CPVC pipe, fi ttings, and cement.
8. A condensate removal pump is required if the boiler is
below the drain. When installing a condensate pump, select
one approved for use with condensing boilers and furnaces.
The pump should have an overfl ow switch to prevent
property damage from condensate spillage. The switch
should be wired in series with the blocked drain switch
inside the boiler (see FIG. 10-1 on page 56).
NOTICE
NOTICE
To allow for proper drainage on large
horizontal runs, a second line vent may
be required and tubing size may need to
increase to 1 inch (25 mm).
The condensate line must remain
unbstructed, allowing free fl ow of condensate.
If condensate is allowed to freeze in the line
or if the line is obstructed in any other
manner, condensate can exit from the boiler
tee, resulting in potential water damage to
property.
1/2" PVC UNION
(FACTORY SUPPLIED)
NEUTRALIZER KIT
FLOOR DRAIN OR
DRAIN PAN
1/2" PVC TEE ASSEMBLY
(FACTORY SUPPLIED)
Figure 9-1 Condensate Disposal
KIT3087 shown for illustration purposes.
Installation & Operation Manual