Combi boiler starts up on its own

[gregg1908]

I have recently installed and commisioned a 30kw Baxi main eco boiler.

It passed all the relevant checks and is running perfectly but the customer said that while he was asleep he could hear the boiler fire up for a number of seconds then go back into standby mode.

I had noticed it firing up once when i had first installed it before commissioning but thought it was a one off as it did not do it again.

Could anyone shed light on the probable cause please.

 

[diamondgas]

Was it a change from a conventional cylinder? And if so how did you isolate the cylinder hot and colds? Sounds like a possible dead leg somewhere?

 

[gregg1908]

It was a straight swap for a non condensing combi to a A rated condensing boiler.

 

[turnpin]

Hello Gregg and welcome I believe some new combi`s have a feature like this to stop the pump from seizing up but not sure if applies to your model some one on here will know regards turnpin

 

[diamondgas]

Interesting ... Could there be a dead leg anywhere? Does it happen when a cold tap is turned on? I know the baxi duotec has a periodic spin of the pump now and again! Does the boiler have a pre-heat?

 

[gregg1908]

Sorry should have said in last post there was no cylinder it was allready out.

 

[diamondgas]

Just checked out the mi's http://www.mainheating.co.uk/docs/main_eco_installation_guide_march2011.pdf .... p9 boiler starts up for 1min every 24hrs to protect the pump

 

[dontknowitall]

Just checked out the mi's http://www.mainheating.co.uk/docs/main_eco_installation_guide_march2011.pdf .... p9 boiler starts up for 1min every 24hrs to protect the pump

Extra electricity used, extra gas used.

How does this get an A rating?

I thought A meant less energy used and it was good for the environment.

 

[GQuigley67]

isnt the vaillant boilers the only true Band A boilers ?

 

[diamondgas]

Extra electricity used, extra gas used.

How does this get an A rating?

I thought A meant less energy used and it was good for the environment.

The duotec does the same ... I thought it just fires up the pump though?

Regards the environment ... Any combi with a pre-heat keeps kicking in every now and again ... Not good especially once they've developed explosive ignition!!! lol

 

[gregg1908]

Thanks all.
Checked out page 9 as i should have to start with.

 

[diamondgas]

Thanks all.
Checked out page 9 as i should have to start with.

Naaaaaaaa! Ya only read them when somethin goes wrong ...

Let those who read every Mi's B4 every job cast the first stone! :rofl: