Boiler modulating down way under flow temp

[Bargain Bucket]

My Glow-worm 24hxi (conventional boiler) has its flow temp set at 70 yet I often find it showing a flow temp of 55 with the burner modulated down to one or two bars. In my simple mind, I'd have expected it to be aiming to hit the 70 by modulating up. What am I missing here?

Many thanks.

 

[fourtytwo]

As I understand it boiler modulation is controlled by RETURN temperature, not flow.
If your boiler is modulating then you have insufficient heat load or the pump is running to fast.

 

[Bargain Bucket]

Ahhh - thanks for that. I'll see what the return temp is and factor that in to my investigations.