Boiler starts when no hot water taps open

[Wookie192]

Hi,

I've just had a brand new combi boiler installed just a few days ago. I've noticed that the boiler will fire up randomly with the tap light flashing meaning it's providing hot water. The only issue is no hot water taps are on/open so I don't understand why the boiler is firing up thinking a hot water tap is being used.

This is happening when no hot or cold taps are in use. What could be causing this as it's using unnecessary gas.

Thanks

 

[Deleted member 120897]

What do your installer say when you asked them? Is any cold water being used at the time, eg a toilet flushing?

 

[ShaunCorbs]

Pre heat ?

 

[John.g]

Some combis have a DHW preheat function that comes on occasionally to get a quick supply of hot water.
Most of these have a ECO light when selected on which means preheat off and vica versa, Eco light out, preheat on. Yours may have a "fancier" way of displaying this, look up the manual or post make/model.

 

[Last Plumber]

As above, it could be preheat function if you aren't using anything or if this happens when you have opened and closed a cold tap or after flushing a WC or during washing machine/dishwasher fill cycle, it could be a dead leg with air in it.