One of the most ugliest installation have I ever seen.The installer shld have used flexible conduit instead of normal rigid piping.But you still can replace it by yr own as u may buy this flexible conduit frm any hardware shop near yr area.Just nid to measure the length.Water heater's can be install thru DIY method.
Btw water heaters no matter what brand the lifespans are normally 5-6 yrs and having a pump in the heater is the prefer choice in Malaysia living.So far the cheapest I have done survey is Joven (less than RM400) and majority of hotels are using this as well......
Oh btw if the pump is noisy no worries at least some indication to others that u r still alive while showering...... Its always safe to test the ELCB once a while

Be warned internal pipes may not be able to stand the pressure especially houses that are old or in poor workmanship on the pipes.It may cost you a bomb to fix it if the pipes burst.Better get expert to run thru it before deciding to fix.My two cents......