Central Heating + showerpump not working, Hot Water Fine

[snowscreen]

Hi All,
I've got a Glow Worm Ultimate 50ff system boiler.

If I use the timer to request hot water, boiler fires up no problem.
If I use the timer to request heating, boiler does nothing, doesn't even attempt to fire.

Was fine on Saturday but Sunday it's not having it.

I had a rough guess that maybe the thermostat is telling it that it's hot enough in the house already? it isn't.
Thermostat is in the hall and is wired into the mains.


Is a system boiler with a Y plan in the airing cupboard alongside the cylinder.
Checked the thermostat wiring and it is receiving power when we try to turn the heating on at the timer.
Stat is a Drayton RTS1


The Y plan, it's called a HORSTMAN F322M,
reviews on screwfix for that model are terrible


As I was looking at that the otherhalf decided to mention a problem with the shower that's just occured.
In the same cupboard as the cylinder we have a power shower pump.

She said that although the shower has hot water it’s at a much lower pressure, turns out the power shower pump is not coming on at all.


Not sure how the shower pump and central heating are related but I guess they are as that would be a big coincidence for both to go wrong at the same time


Any ideas?
Could a faulty Y plan still cause both the problems, or could the power shower pump have caused both?

Had to leave for work so ran out of time to look into it further

 

[dcawkwell]

Are you getting 240v from the programmer when it is switched to central heating? If not programmer fault.

Have you got 240v at the thermostat when central heating switched on.
If not thermostat fault.

Have you got 240v on the orange wire at the 3 port valve when central heating switched on. If not 3 port valve fault.

Sorted.

 

[snowscreen]

Ok,
So I've detached the actuator from the 3 port valve.
The spindle moves by hand, only a little both ways but it does look like I can move it by hand just as much as the actuator would move it when using the manual override lever

So it appears it's not seized.

When turning the central heating on the actuator light comes on so it's getting a signal, but there is no noise at all from the actuator.
I presume I'd hear the motor slightly when requesting the central heating as it would need to move the spindle?

What actually tells the boiler to come on anyway? is it the actuator.
If it is the actuator that's at fault not sure if I can just replace the motor/actuator on this or whether I'd have to buy a whole new 3 port valve set (then only use the head)