Alpha 240 P/E Combi fault !!

[Systemfix]

Hi guys,
hope you can help, I came home after a week to find my flat with a large wet patch under the bolier, I immediately opened the cove to check, I noticed dripping from the left side bottom, see pics, its a small plunger that activates a small black switch when the hot water is turned on and goes back when turned off. Water is emerging from around the pin hole, its a constant drip. What is this part called and any idea on how to replace this part?
Any pointers would be very greatful,
thanks in advance..

 

[petit_pablo]

Its the gland nut on the hot water flow switch that is leaking by the sounds of it.

You can get a service kit for the hw valve that includes a diaphragm and gland nut. Its easy to do. Turn off mains water and electric, open hot tap thats lower than the boiler. Remove microswitch and undo 6 screws. replace diaphragm (its probably going to be stretched so may as well do it at same time). Undo gland nut from front of valve and replace. Put back together the same as it came apart.

 

[Systemfix]

Thanks very much for your help but after ive replaced the diapham and gland nut do I just turn the mains back on and electric or do I have to refill/repressurise the boiler?
thanks again

 

[petit_pablo]

Just turn mains back on, you shouldnt be touching the system side of the boiler