Boiler not firing up

[Bowbeyboy]

Hi All, I'm no expert but I'll try to be as accurate as possible and it would great if anyone can help I have a Valient VCW Sine 18 T3 combi boiler, which is old but built like a tiger tank! The problem is that I cannot get any hot water, neither heating or hot water. The pilot is on OK, all rads bleed and balanced, the four bled points on the boiler also bleeding ok. The expansion vessel is pressurised OK on the air side (pressure when I press the valve and no water). The Diaphram in the water section was changed about a year ago. So when I turn on a hot tap on i can hear the pump ect and it seems to be trying to fire up, but never actually does it, though the flames do very slightly appear if you leave the tap running for about 5 minutes. Any help appreciated ;O)

 

[Agile]

Right in the center there is a black plastic bit with thin tubes going back to above the pump.

That usit has a pin on itsd rear which needs to come out to push an interlock pin on the gas valve.

You can see that with a small LED torch. You should seee the pin coming out about 7-8mm when the pump starts. I suspect its not moving at all or enough.

Either dirt in the tubes or the pump is weak or impeller is blocked.

Tony

 

[Bowbeyboy]

Hi, thanks a million for that, I drained the boiler and dissasembled the component, the diaphram was ok so I gave everthing a clean and greased the pin which seemed a little stiff in the housing. After refilling and bleading it fired up lovely! I enjoyed a hot shower! However this morning again if wasn't firing up so I think as you suggest the pump may not be working 100%. I'll carry on examining !

Thanks again.