boiler not right

[ZakUK]

hi
this is my boiler: http://i202.photobucket.com/albums/aa188/Negerove/20130121_174639.jpg in a heating mode (the amber light came on eventually)
When heating is not needed anymore, we turn the small switch (in a middle of a picture) to the right and boiler stops working, all lights off. If someone uses the hot water, boiler will turn ON and produces hot water, water off, boiler off.
Yesterday, finished heating, switch turned to the right, but the green light (one of three) stayed on and every hour boiler would start up, work for a minute and then shutdown.
Checked this morning, the small green light still on and the display was showing 54 degrees, although no heating was done during the night.
So i turned the WATER control round handle completely to the left and the green light went off and so far boiler is not starting up itself and temperature is going down.
So it seems that boiler was starting up constantly to keep water temp high.
Now turned the wate handle back to the same position as in a picture) and so far the green light is off, the boiler is sleeping.

So my question is: why it was turning itself ON from time to time ? Should i have someone to look at it ?

thx
thx

 

[ALEC1]

LOL...its the hot water preheat....

read the instruction book to turn it off..but there are advantages to keeping it going!

 

[ZakUK]

so how come it never did the preheat before ? Mind you, the small switch is turned to the right, not the middle. and the timer "empty", not set.
i know the preheat works when the switch is in a middle position, thats why i posted the original question

 

[ALEC1]

I really would read the book.. the preheat is activated probably by turning the knob clockwise and then back with in 2 s...something like that..

I guess you are a man...women tend to read the instruction books!

 

[ianmcd]

To turn the HW pre heat on you turn the HW temp control knob to Max and the green light will come on, to turn the pre heat off turn the HW temp control to min and green light will go off then turn stat to whatever temp you want except max or the pre heat will come on again