My Central heating wont come on. There doesnt seem to be any lights on the boiler/burner. Why could this be. First time I've tried to turn it on this season...it was fine back in february. Thanks!

It sounds like it has been mis-wired. The circulator pump should run all the time the boiler is on and should continue to run when heat is called for so it circulates the water in the radiators as it cools. There is normally an electronic valve that shuts flow to the radiators when only hot water is needed. Call for heat and that valve opens. It sounds like you need a mature, old school boiler / central heating technician who has lots of real world experience with older boilers.
https://www.youtube.com/@MiHeatingGuy

If you have a large screwdriver, you can use it against the pump as a stethoscope to listen for the pump running. The noise is very distinctive.

Combi-boiler-turn hot water tap on/off and the heating stops for ...

singletrackworld.com/.../combi-boiler-turn-hot-water-tap-onoff-and-the-...

Combi-boiler-turn hot water tap on/off and the heating stops for 20secs ... hot watertakes priority over central heating so when you run the hot tap, heating is ... Yeah onmy worcester combi there is a diverter valve - it feeds either the heating or ...

My central heating works but I have no hot water - 24'7 ...

https://www.247homerescue.co.uk/my-central-heating-works-but-i-have-...

Diverter valves switch heat between the hot water and the central heating. When youturn your hot tap on, the diverter valve temporarily shuts off the water supply ...

Does your boiler keep switching itself off? Here's why ...

www.dhs-uk.com/does-your-boiler-keep-switching-itself-off-heres-why/

Jul 7, 2015 - ... Bathroom Suites, - Showers, - Wet Rooms, - Taps and Accessories, Information and ... Low water pressure can cause your boiler to turn itself off. ... boiler is not turning off, you aren't getting the amount of hot water you require. ... If there is air in your central heating system, then your boiler may shut down.

The water isn't maintained hot (unless the central heating is on) in a combi boiler. you will, therefore have to turn the water on, which activates the burner. The burner will then have to heat up the heat-exchanger which then supplies the hot water through cold pipes. Once the pipes are warm, you will receive hot water.

Did you bleed the air from the pump .

Hi - hope someone can help. I have a VOKERA EXCEL 80SP combi boiler and been without hot water/central heating for two days. The pilot light is on, the fan is on, but boiler not triggering once the hot water tap is turned on.
Hopefully someone come to look at it today but hoping for some advice. Anyone else had this problem?
Thank you.

it could just be the presure switch try bridging it out and see if burner lights

it sounds like your shut off valve might be bad even though it turns on and off by turing it doesn't mean that the washer is not stuck to the seat and not opening, try replacing the valve

boiler may need more pressure in system pressurise to middle of green between 0.5 bar and 1.0 bar

the stat works using a bi metalic strip so that click you here is making a contact and telling the boiler to call for heating so if you getting no click you need a new room stat. Replace with same model and note the wiring most stats only use 2/3 wires depending on system

having found a circuit diagram, realised that the divertor valve was electrically operated.i unplugged this then unclipped the motor from the valve body,the diverter valve is spring loaded and once i'd removed the motor the spring raised the valve to divert water through the dhw heat exchanger,giving us hot water but no heating, if i refit the motor the problem comes back heating no dhw.ordered new motorised valve assembly £30 next day order .
this was a simple fix without having to drain the system down.