B
buckley plumb
been to a main eco today about 3 years old. heating is fine but on hw boiler would not modulate seemed to heat water and turn burner on and off - fitted hw thermistor as hw thermistor fault come up occsionaly. this seemed to help and when the hot tap was turned on full the boiler would modulate - turn tap to half flow burner would hunt up and down trying to modulate down after 2 min it would modulate to low and be ok .I am thinking now heating thermistor as this controls the primary flow