Boiler - Central Heating

[essexpaul]

I have an issue which may go over my ability and may need a registered tradeperson. I have a Ideal Logic Heat 12 boiler and it is on time and come on at 630am and off at 8.30am and on at 4pm and off at 10am. However the boiler fires up between these times and go on for about 5 minutes before turning off again. The CH and HW lights on the timer do not come on. This could happen during the day and mostly at night including one time where I had to turn the boiler off at the timer. Can anyone confirm if this is a boiler issue or is the timer not working. They are danfloss. HELP

 

[essexpaul]

Sorry should say 10pm

 

[oilmark]

It may be a frost stat activating in this cold weather.

 

[essexpaul]

Thanks for reply. Would the boiler have one because to get the frost protection in action I have to turn boiler off which then automatically put the frost protection on at 5C.

 

[doitmyself]

Where is the boiler located - in the house, or the garage?

 

[essexpaul]

In the kitchen

 

[Belli]

Sounds more like a sticky port valve not fully switching

 

[essexpaul]

Had heating engineer in and he checked the system and said he can see no problems and that the heating will kick in overnight every time when the temperature falls below 20degrees but only upstairs. Don't think that is correct as surely should only come on when it is timed to come on.