valiant combi Bangs then died

[james4204]

Hello all
I have just moved into my first flat, as it is freezing first thing i done was turn on the heating, this fired up ok, and heated the radiators. about 15 mins later they all went cold and the boiler was totaly dead!
the internal fuse in the pcb had blown, this was replaced and the boiler then turned on.
now the water heats, the pilot light comes on but it then makes a loud banging and gurgling , and then stops, no hot water is pumped to the rads.
i have soemone coming to look at the boiler on tuesday, and knowing nothing about boilers, i don't want to be ripped off!!
could this just be air in the system causing the pump to run dry ? i have bled all of the rads but not sure how to bleed the boiler.

it also has since blown another of the 2a fuses.

any suggestions would be great!
james

ps , i forgot to add i cant find the model number ANYWHERE on the boiler. the boiler was ment to be serviced recently ( not sure if it was ) but the main PCB seems to look newer then the rest of the system (again told this was changed )

 

[kevplumb]

any suggestions would be great!

boiler model might help

is the pump running


is the system pressure at least 1 bar cold

hope this helps

signed

rip off plumbing ltd

 

[james4204]

the pressure is about 1.5 bar
not sure if the fan is running, but the banging ( and gurgling ) sound starts when the pump starts to kick in, this happens for a few seconds, then all of the lights go out, apart from the 0/I power light , and it just "sits there" a few mins later is tries again, and again it bangs, gurgles and then gives up!

unfortunatly i cant see a model number on the boiler, where would it be shown? as i have looked around and seen nothing but the make vaillant

 

[kevplumb]

depending on the model it has an auto air vent either on the pump or at the top rear of the boiler casing is the cap loose

 

[james4204]

im not sure, being a fick newbie to boilers, what would this auto air vent look like? my friend who diagnosed the fuse said there is possibly a air vent on top of the pump, guess this may need a twist!!

 

[kevplumb]

 

[james4204]

ahhh yes, that looks very much like what is on top of the pump!!
i assume i tighten the black part on this!!
would i need to get any air out of it anyway , or do i assume from the "auto air vent" i tighten this and then cross my fingers?

 

[james4204]

oh, and would this cause the fuse to blow?

 

[kevplumb]

i tighten this and then cross my fingers?

try slackening the black cap to let the air out

 

[james4204]

ok, ill do that!! thank you