Heating is on but house is cold and radiators are cold

[KVV]

Heating is on but house is cold and radiators are cold.

Heating and and Hot water was on schedule , it seems hot working fine but heating seems to be not working 

in current temparatures, it is frustating, anyhelp ?

thinking of removing this  NEST LEARNING THERMOSTAT

[Frustratedddd]

You might need a little more information for help.

What heating are you using?

New setup or old?

The heating temp, what is that set at?

Can you see if it's calling for heat?

Can you confirm your pump is running?

[KVV]

Potterton boiler - system boiler i think 

Set up was old - 3 years ago installed

Heating temp 23 c

i can't see heat link icon for heat is on  - when i set in dialler or app setting

pump - not sure what do you mean 

Thank you for your help 

[Frustratedddd]

System boiler is Heating and Hot Water with a cylinder

The pump is the unit that circulates the water round the system. When the stat calls for heat the pump will run to heat the rads, then you will know the water is circulating/pumping round the system. When that fails you will not get any heat out of the radiators. I am just suggesting, as it could be a motorised valve.

The Nest is it a 3rd generation?