I have put on one of those clip on dial thermometers on the flow pipe from my old Mexico boiler and found that on the max setting the water temp was only getting to 62 degrees but the boiler manual states it should be 85 on max.
Thinking that the stat was faulty I replaced it with a new one but the water temp was the same so what would be the reason for the low temp.
I tried running the boiler with the thermostat phial removed from its pocket and stopped it when it got up to 75 so the boiler will get the water up to the temp but the stat seems to be stopping that happening.