Vaillant VCW-Sine....T3W. Boiler stops & starts

[Khalid]

When it works, all functions i.e. Central Heating and Hot Water with/without instant water switch works for anything between 10 minutes to 2-3 hours. When it suddenly stops, nothing works.

Had someone to fix it he fixed the pressure by removing overflow valve and cleaning it. Pressure does not drop now. He has replaced a part which is connected to three pipes including inlet pipe and to the Electric Control Panel It is situated underneath the E.C.P. and a pin goes into the panel. This part also has a diaphragm inside it.

Now he is saying that pump is sticking which needs replacing. I have removed the nut in front of the pump and pushed the piston with the screw driver but it did not start working.However when I hit the side panel where the pump is, its comes on. But not always.

I hope all this is making sense to readers!

Please help!!!!!!!!!!

Khalid

 

[oilman]

Your pump is obviously sufferering from fear of getting a good thumping, and so is doing its best to avoid drawing attention to itself and is petrified with fear.

If you've been pushing the "piston" on the pump, what type/make of pump is it? Most pumps are rotary, and the spindle under the access screw needs twisting with a screwdriver.

 

[Khalid]

Mr Oilman
Enjoyed reading your reply, thanks for that!

Your are right pump is rotary and when I turned it clockwise/anti clockwise, it did not start.
Body of the pump gets very hot, is it due to hot water flowing through or something else?

If its left alone, its come on after a while. Perhaps my thumping has got no effect except hurting my own hand.

Could it be some thermostat?


Pump's Make is Vaillant
Type: VP 5-SEZ
Model No. B D G
class F
Frundfos

Regards

Khalid

 

[oilman]

I think it's getting hot because the electricity is trying to turn it. Try rotating the pump shaft backwards and forwards a lot it should feel very free, if it doesn't it's probably a new pump, about £23 from screwfix.