Vaillant boiler cutting out

[ADCG22]

Hello all

I have a Vaillant Turbomax 824E - when there is a demand for heating everything fires up as it should, after several minutes the heating turns off even though the digital room stat still indicates a demand for heating. The pump overrun remains on for ages afterwards.

The rads nearest the boiler get hot but the further away rads in the living room and bedroom remain cold or warm.

I have had a new heat exchanger and diverter valve fitted due to a hot water problem recently also FYI.

Does anyone have an idea of the problem?

Many thanks

 

[spraggo]

Hello all

I have a Vaillant Turbomax 824E - when there is a demand for heating everything fires up as it should, after several minutes the heating turns off even though the digital room stat still indicates a demand for heating. The pump overrun remains on for ages afterwards.

The rads nearest the boiler get hot but the further away rads in the living room and bedroom remain cold or warm.

I have had a new heat exchanger and diverter valve fitted due to a hot water problem recently also FYI.

Does anyone have an idea of the problem?

Many thanks

Suspect faulty pump, either start up capacitor knackered or pump binding.

 

[Agile]

He says the pump remains on for ages so unlikely to be a pump fault.

But to make any guess at the fault I would want to know what it does on hot water!

I suspect so far that the diverter may not be moving fully. Was it brand new or repaired?

When the heating is on, how warm are the two boiler pipes?

Tony

 

[ADCG22]

Thanks for your replies.

The flow and return pipes are both hot when the heating is on, the pump is hot also. I turned off all rads apart from the furthest one in the bedroom and this heated up very well - when all the rads are on this bedroom rad doesn't heat up.

The diverter valve was a brand new Vaillant part.

The hot water is fine - when the shower is on the burner ignites and does switch off then back on then off then back on during the duration of the shower. There is a minimal difference in water temperature, is this normal? Before the new HE the this would happen but the water would go cold then warm then cold then warm. Should the burner be on constantly when there's a demand for hot water?

When the display on the boiler reaches 68 degress (when heating is demanded) it stops.

Thanks

 

[Agile]

I suspect the gas settings may be wrong. Not a DIY job though. Run a hot basin tap at half flow and see what happens.

Sounds as if you may just have a balancing issue. See FAQ

Tony