Vokera Syntesi Fires Without Demand

[JDH90]

Hi everyone,

I have recently moved house and updated the thermostat to Hive. Ever since, I’ve noticed that the boiler (Vokera Syntesi 25 E) has been firing once every hour or so, without CH or HW, for around 30 seconds. Is this normal?
I cannot remember noticing this before I installed Hive but I also don’t remember much from yesterday so it could have been happening the entire time.
If it’s not normal, could it be Hive, or would it be a fault with the boiler?

Thanks for any help.

 

[ianmcd]

Your boiler has a domestic hot water pre-heat function, if the boiler primary water system drops below 35 degrees C the boiler will fire briefly to keep the water in the boiler hot so that when you run a HW tap it will come out at temp faster, that is your most likely culprit, this function can be disabled , you need to access the PCB and there is a jumper on JP6, if you remove that the pre heat is disabled, tells you how to do it in the installation instructions, sounds really technical but it really is very easy to do, will save you a bit on gas bills but not a great amount, if it doesnt really bother you then just accept that it is doing what it does, it is not a fault, it is just what your boiler does, more modern boilers you can enable/disable this function via the control panel, unfortunately with your boiler it is a manual operation on the PCB

 

[JDH90]

Thanks ianmcd. Think I’ll leave it on since it’s not an issue.