Swimming pools blog

My piece of junk Sta-rite propane heater is leaking.
Looking at the parts diagram it looks like there is about 15 o-rings
and gaskets between the water inlet, heat exchanger, and outlet. Is
this normally the problem when they start leaking. It looks fairly
simple to disassemble and start changing out o-rings. Has anyone
done this before? My thoughts are if the heat exchanger coils are
leaking replacement parts are about $600.00 at that point would it
be worth repairng or is it time to replace. The Unit is only 4
years old