Technical data

GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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Before commencing any maintenance or servicing work the heater must be shut down and allowed to
cool, and have the gas and electric supplies to it turned off at the supply cock and isolator respectively.
Always test for gas soundness after completing any service work particularly if this has
necessitated the removal and / or replacement of gas carrying components
It is advisable that routine inspections are carried out on a frequent basis, servicing must also be carried
out regularly, and in accordance with the manufacturers recommendations i.e. at a maximum interval of
one year. In certain applications the frequency of servicing will have to be increased, this to a large extent
is governed by the working environment, and both the manufacturer and the installer will be able to offer
further advice.
A safe working platform giving good access to the heater is required, It should be noted that on
suspended units the lower front panel is removable so as to provide access to the burner tray, injectors,
and manifold, all of which should serviced in the normal way as detailed.
Clean all accessible surfaces including the outside of the heat exchanger by removal of the fan assembly
and the louvres. Check for panel damage and that all fasteners are present and secure.
Visually check all electrical wiring for signs of damage, possibly through contact with hot surfaces,
check conduit for signs of chaffing and for security . Check all terminals are secure and free from
escaped / stray conductor strands.
4.1 Servicing procedure - major component parts
Heat exchanger
Remove louvres and fan assembly and carry out visual inspection of the heat exchanger using an
inspection lamp and mirror. Check seams and joints for perforations. Check for severe corrosion and
splits in the body in the body of the heat exchanger.
Check that there are no blockages and that there is not an excessive build up of soot within the heat
exchanger.
If required remove the down draught diverter and burner tray allowing access for cleaning, with a
flexible flue brush and vacuum cleaner.
Warning
If the heat exchanger is found to be perforated the heater must not be fired until a replacement heat
exchanger has been fitted
Burner Pilot
Remove the right hand side panel. Disconnect the pilot gas feed at both the gas valve and pilot bracket.
Disconnect the piezo HT lead from the terminal. Unscrew the thermocouple retaining nut from the pilot
bracket and withdraw the thermocouple. Remove the two retaining screws and withdraw the pilot bracket
assembly. Clean the thermocouple. pilot bracket and pilot burner ports with a fine wire brush and / or lint
free cloth if necessary using acetone
Caution
Where pilot gas lines are of copper aluminium or bundy tube feed pipes should be undone at both ends to
prevent undue stressing and the risk of premature failure.
Burner Tray
Caution
Burner tray cannot be removed with the pilot assembly in place
Remove the two screws from the hinged front panel and open the panel fully. Remove the two burner
tray fixing screws located on the right hand side inner panel. Pull tray forward and if required clear of the
heater. Clean the burner ports with a vacuum cleaner, fine wire brush, and / or lint free cloth and
acetone. Visually inspect the burner ports ensure that they are all clean and unrestricted , if necessary
using compressed air to carefully dislodge and remove any foreign matter.