Powrmatic Air Heater NV90-F

Disconnect electrical connections

Pull off the sensing tube from the air pressure switch

Note the setting of the old pressure switch

Remove the screws fixing the air pressure switch and remove switch

Installation of New Pressure Switch

Fit replacement in reverse order

Refit the sensing tube to the negative (- or L) tapping on the pressure switch

Disconnect the electrical connections to the centrifugal fan section

Remove the side panels of the section for access to the fan and motor

Fit replacements as appropriate

Is a 3-phase motor being replaced?

Is the direction of rotation correct?

Remove the burner assembly as described in Section 7.2

Remove the end plates of the burner assembly

Remove the central burner support plate

Reassemble components in reverse order

Re-commission the appliance as described in Section 6

Inspect the fan blades for damage and excessive deposits

Is it necessary to remove the assembly for cleaning?

Slacken the cable gland on the heater casing

Disconnect the fan leads from the electrical terminals on the PCB

Withdraw cable through entry grommet

Remove the fan and motor assembly by removing the four hexagon headed bolts

Remove the burner assembly as described in Section 7.2

Multifunctional Control Removal

Release the flanged connections at the inlet of the multifunctional control

Release the flanged connections at the outlet of the multifunctional control

Remove the multifunctional control

Reconnect the new valve in reverse order

Ensure the valve is correctly orientated