CleaverBrooks ClearFire CFH, Operation, Service And Parts Manual

Page: 63 / 120

Chapter 4 — Commissioning
Part No. 750-295 4-21
4.13.5 Low and High Fire Adjustments
All CFH boilers are factory tested firing natural gas at an altitude of
1000 ft ASL. Operating under different conditions may require re-
adjustment of the gas valve.
Adjustments are made using a TORX® T40 (low fire adjustment) and
3 mm hex wrench (main gas choke). The adjustment screws should
initially be set to half way through each setting’s range. The low fire
adjustment screw is accessed by removing the slotted cap on the gas
regulator using a blade screwdriver (see
Figure 4-17 ). The high fire
adjustment screw is accessed by removing the blue plastic cap from
the valve cover (see
Figure 4-18 ).
Turn the adjustment screw completely clockwise, counting the turns
until the screw will no longer turn. Then, turn the adjustment screw
counterclockwise half the number of turns counted when turning
clockwise.
NOTE: When adjusting low fire offset, clockwise adjustments increase
gas flow, and counterclockwise adjustments decrease gas
flow.
When adjusting the main gas choke, clockwise adjustments
decrease gas flow, and counterclockwise adjustments
increase gas flow.
CFH 70-80 HP and Low Gas Pressure Option
See figures below for low and high fire adjustments on the CFH 70-
80 HP and 30-60 HP with low gas pressure option. Both low and high
fire adjustments are CLOCKWISE to INCREASE gas flow.
When making low fire adjustments, the protective slide on the bottom
of the valve must first be opened. Close and secure the slide when adjustments are complete.
Figure 4-19 Low fire adjustment - low gas pressure option
Figure 4-17 Regulating Adjusting
Screw - Low Fire Adjustment
Figure 4-18 Main Gas Choke -
High Fire Adjustment
Protective slide
After setting the required pressure :
1. Close protective slide.
2. Secure protective slide closed
with a screw.
Metric
Allen Key
No. 2.5
LOW FIRE