Conventional boiler - Water is not hot enough

[DaniQ]

I moved in a house with a Vaillant Thermocompact 620e boiler with an insulated hot water cylinder.

The heating works OK but the water for the bath and taps doesn't get hot enough. I have the hot water "wheel" turned to the maximum and i get water at 35C after having the boiler on for 4 hours

Is there any way to increase the temperature to something like 50C?

Thank you.

 

[ShaunCorbs]

What does the cylinder stat read ?

 

[DaniQ]

What does the cylinder stat read ?[/QUOTE

 

[jtsplumbing]

What temp is boilerr stat set to ? what is cylinder stat set to ? could be a number of things , Fault with boiler stat, or something else with boiler, Faulty cylinder stat, or 3 way valve faulty,

 

[ShaunCorbs]

The box with the white band around the cylinder

What's that set to

 

[DaniQ]

Is the boiler stat the grey thing on the left of the cylinder or the white smaller box attached to the cylinder?

 

[DaniQ]

70

 

[ShaunCorbs]

70

That should be on 60

And no that's the port valve grey box with 3 pipes connected

Pic of your boiler with the flap down please

 

[DaniQ]

Which position the 3 way valve should be set to? W M H?

 

[Stigster]

You don't set that. That's an indicator to show what position the valve is in at any given time. Water/Mid position (both on)/Heating. It's open to the hot water side in that pic.

 

[clemda1]

You don't set that. That's an indicator to show what position the valve is in at any given time. Water/Mid position (both on)/Heating. It's open to the hot water side in that pic.

Could be one of three things? 1) the programmer, 2) cylinder stat or 3) 3 port valve. Simple tests you can do:
Set cylinder stat to 60deg
Set programmer to hot water only
Confirm the boiler fires (assuming the pumps is working ok as you said the heating is ok)
Now on the diverted valve feel the pipe going to the cylinder (cylinder flow pipe) this should pretty soon star getting very hot ( to hot to touch) and should stay hot until the cylinder reaches temperature (60eg)
If not report back as to what in the above sequence did not happen and we can help further.