Install Instructions
CHS Series Installation and Operation Instructions │ Slant Fin Corp.
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Mandatory Pre-commissioning Procedure for Plastic Venting (PVC or CPVC)
Do not apply power to the boiler prior to Step 4 in the Mandatory Pre-commissioning
Procedure for Plastic Venting.
1) Working with the power turned off to the boiler, completely install the vent and air intake system, securely
cementing joints together. If possible, allow primers/cements to cure for 8 hours before firing the burner. If
curing time is less than 8 hours, proceed with Steps 2 through 6.
2) Maintain the boiler gas supply shut-off valve in the off position.
3) Remove the cable from the Spark Ignition Transformer.
Spark Ignition Circuit - Maintain a safe distance (2 inches minimum) from the spark
ignition circuit to avoid injury from electrical shock.
4) Turn power on to the boiler and apply a heat demand.
5) Allow for 3 complete trials for ignition, consisting of pre and post purge of the combustion blower, until an
ignition lockout occurs. Repeat the process two more times (i.e. 9 complete ignition sequences in total).
6) Turn power off and reconnect the cable to the Spark Ignition Transformer.
Vent/Air-inlet Pipe Length Determination
Use Table 4-5 to determine the maximum pipe length that can be used. The table calculates 90º elbows, and 45º
elbows at 5 equivalent feet each.
Example: When using 3” pipe, a CHS 85-110 can be installed with 150 equivalent feet of air-inlet piping and
150 equivalent feet of exhaust-vent piping. See Table 4-5 for more details.
Models CHS 85-110 require a minimum equivalent exhaust vent length of 15’. When
operating on Propane, models CHS 85-110 require a minimum air-inlet length of 6’ and
11’ for 2” and 3” venting respectfully.
Table 4-5 Allowable Vent and Air-inlet Pipe Size and Lengths
Model No.
Pipe
Size
Gas
Length
(ft)
Number of Elbows (90’s or 45’s) and Equivalent Feet
1
2
3
4
5
6
7
8
9
CHS 85-110
2”
1
NG
100
95
90
85
80
75
70
65
60
55
CHS-85
LP
35
30
25
20
15
10
5
-
-
-
CHS-110
25
20
15
10
5
-
-
-
-
-
CHS 85-110
3”
NG/LP
150
145
140
135
130
125
120
115
110
105
CHS 155-250
100
95
90
85
80
75
70
65
60
55
CHS 300-399
4”
100
95
90
85
80
75
70
65
60
55
Note:
1
See WARNING below.
PVC Exhaust Venting – When using 2” PVC venting with models CHS 85-110, the first
seven (7) equivalent feet of exhaust venting must be approved 2” CPVC or 3” PVC; see
exceptions in Table 4-4 and Figures 4-2b and 4-2d.