Baxi eco 80

[growlerr]

Gentlemen/ladies i have a problem - my sister has a baxi eco 80 which was working albeit on the DHW side selector switch only - i noticed that the boiler pressure gauge was showing 0 - i filled it up via the filling loop to 1 bar then vented rads and topped back up to 1 bar turned the selector switch to Heating and Hot Water and nothing! - when i turned a hot tap on just the pump ran no boiler fire up - turned the room thermostat up pump runs and nothing else no fire up no fan running - nothing. As you can imagine i'm not on her christmas card list, so i really need to get this sorted how can the boiler work then not work just by filling up the heating loop - any answers however far fetched would be greatly appreciated

 

[dcawkwell]

A number of possibilities.

1. Trapped air in the boiler so there is no flow registering.
2. Flow sensor fault.
3. Diverter valve fault.
4. Pump fault.

Try wacking up the pressure say 2 bar and see if anything moves.
You can always drop it back by bleeding a radiator.

 

[growlerr]

Thanks for that - ihave to say there did seem to be a lot of air rushing around the system after i filled up but i think automatic air vent shifted that - if it didn't how do i get rid of any air left in the boiler and would it actually stop the boiler firing up even just on the DHW setting - as the pump runs when hot water is called for and when central heating is calling for hot water would there be a fault in the pump - i'll check the other things you mentioned and let You know - well here goes!

 

[dcawkwell]

Thanks for that - ihave to say there did seem to be a lot of air rushing around the system after i filled up but i think automatic air vent shifted that - if it didn't how do i get rid of any air left in the boiler and would it actually stop the boiler firing up even just on the DHW setting - as the pump runs when hot water is called for and when central heating is calling for hot water would there be a fault in the pump - i'll check the other things you mentioned and let You know - well here goes!

There is an air vent in the boiler but if this was blocked you could have a nasty pocket of air in the boiler.
Pump could be running but just turning in air.
Either way the flow switch isn't getting any flow to tell the boiler that water is moving. That or the flow switch is faulty. Since it was working I'd have to go with the air guess. If the pump is running can you hear it moving water in the radiators??

 

[misterdubya]

Carefull, Agile will slate you in the CC for this advice.

 

[growlerr]

When i turn on a hot tap water runs freely out of it and the pump comes on - no boiler fire up - when i turn the selector switch to heating and hot water pump kicks in and i can hear water movement in the boiler itself - i haven't checked for movement in the rads though, will check that asap - after about 5 mins the pump does start to warm up if that's any indication of something but again no boiler fire up - will have a look at the air vent to make sure that its functioning correctly and then try and get rid of any air that's left in the boiler