I have a problem with my alpha boiler it fires up and keeps going on and off especislly on the hot water

Thermostat on boiler . or hot water sensor .

What boiler do you have and is the controller a radio controlled thermostsat

It could be dyslexia, but I think you want to know what may be wrong with your boiler in this case!
This is a VERY old design. The diaphragm is on the water section, this operates a switch to turn ON the pump, and a further device causes the diverter valve to divert boiler water from CH duty to HW duty.
From your description it appears that the boiler is shutting down on internal boiler water temperature (too high), your 'briefly too hot' HW symptom may be caused either by the boiler side of the secondary heat exchanger being blocked/caked in sludge, OR the DHW side of it being scaled. Either way a new or replacement (descaled) secondary heat exchanger MAY inprove things. It's not easy on these old clunk-pots, and EVERY disturbed seal will subsequently leak, so get a good supply of o-rings and fibre seals before you start ("you" being the competant fitter you employ)

Let's see what we can do to trouble-shoot this boiler--

First of all-- Are we talking about a Hot Water 'Boiler'-- In other words does this boiler heat water that circulates thru the house, to keep you warm?

Next-- What is your fuel?

Have you Shut the system down, to reset it?-- What happens when it comes back on again?-- Clicking sounds-- pumps trying to start-- solenoids trying to open, etc.-- Tell us what you observe-- so we can help you trouble shoot this problem.

Mack B

what are the lights doing on the boiler when its cutting out

there is 2 taps on the filling loop

its diverter or the flow switch

It doesn,t like your boyfriend

most likely the diverter valve.. when hot tap turned on the movement of the water through the valve operates a diaphragm which pushes a pin/button//switch to tell the boiler to fire up

Problem is normally the hot water flow switch -