Thread: Hot water system troubleshooting (bosch water wizard 780)

Very dangerous country your playing in there mate !! Have you checked that your gas supply is still OK e.g valves 1/2 shut empty bottle etc?? The only other thing I would recommend would be to get a Plumber/ Gasfitter ( preferably at mates rates ) to cast a learned eye over it. Don't blow yourself up for the sake of a couple of bucks. :eek:

Double post Damm!!

Sounds like the same problem as I had a few months back, on the same model, but don't know how someone could do the fault.

There's a round rubber diaphram that when water flows pushes up a small metallic rod and lets the gas flow. In my case it was badly corroded and was only partially pushing up and was resulting in a small flame, not the usual large flame inside the unit. Cost around $150 all up to have it replaced. The new ones are newer plastic stuff (polysomething) and last longer. If you do pull it apart, its quite likely it will be damaged and won't work until a new one is fitted.

I don't think it needed to do any gas work, but at the sake of blowing yourself up I'd be using a gas fitter. 1/2 hr job.

Have you checked for other problems first, gas supply to oven ok, gas valves on and the regulator at the meter looks normal ?

hehehe, i've given up, got a guy coming out over the weekend ...

thanks guys,

ended up trackin down a friend of the family, fkn legend!

he came out at 730, worked on it till past 10 ...

pulled it apart, the heat issue was related to a blown thermostat which he replaced, along with the entire aluminium unit (the knobs & stuff that connects to the copper bit down the bottom) and serviced it (replacing the diaphrame & a couple other little things that come with a service)

basically overhauled the lot, the aluminium bit was still working, but severely corroded ...

anyways, in case anyone has similar problems, no heat is likely the thermostat