Hi there Bernhard Siefert... (G'day)
(from the other side of the date-line
.. going out on the SF Bay today to watch our Blue Angels (again))... God Bless them...!
Easy to do...
(network search) Just search on your right combo...
"Teledyne Laars spares service Melbourne Australia
and got (after wading thru a lot of SF malarkey)
Spa Pool Gas Heater Repairs Service Conversions Maintenance
Try it yourself ... your results will probably be better...
There are lots of heater questions and answers on this site if you were thinking about getting your heater running quickly... but if you are un-comfortable with tubing wrenches and GAS heaters...
a qualified service technician usually SEEMS to be the safest approach.
I've always done my own repairs... because leaving explosives in the hands of rookies and apprentices scares
me... and life is good.
Good luck... be safe!