Page No 44 of 56 Reznor, RHC21 4000 Installation EN May 2021 D301334 Issue 0
5. The thermostats can now be removed from
the mounting bracket.
6. Replace one or both thermostats as needed.
Ensure sensor is pushed up to the return
at the end of the bracket and secured in
place with the retaining clips. Replace clips if
necessary. Ensure thermostat is held tightly
by the retention clips. It may be necessary to
close the clips with pliers before fitting the
thermostat.
7. Refit all parts in reverse order. Press LC3
button to reset thermostat.
8. Seal gaps around thermostat mounting
bracket with silicone sealant to maintain the
integrity of the burner compartment.
9. Follow start up and commissioning
procedure.
7.8 Replacement of ignition controller
1. Disconnect all electrical connections.
2. Unscrew fixings located in the corners of the
controller.
3. Remove program key and refit into new
controller.
4. Fix new controller to electrical panel and
reattach all wiring.
5. Follow start up and commissioning
procedure.
7.9 Replacement of ignition
transformer
1. Disconnect all electrical connections.
2. Unscrew fixings and remove transformer.
3. Refit in reverse order.
4. Follow start up and commissioning
procedure.
7.10 Replacement of lockout circuit
board
1. Disconnect all electrical connections.
2. Pinch circuit board retention clips to release.
3. Refit in reverse order.
4. Follow start up and commissioning
procedure.
7.11 Flue and combustion air
Check the complete system at least once a year.
The inspection should include all joints, seams,
concentric adapters and the flue terminal cap.
Replace any defective or heavily corroded parts.
7.12 Unit operation
The combustion and correct operation of the
appliance should be verified as a part of the
normal service routine. Follow the steps in the
start up and commissioning procedures to verify.
Silicon sealant
around
mounting
bracket
