Vaillant ecoTEC plus 831 anti cycling

[phxgs1]

Hi

I have had an ecoTEC 831 installed recently. With CH temperature set to 60C, the boiler runs up to that temperature and within a few minutes the burner shuts off and the temperature slowly falls to around 35C before the boiler fires up again and repeats the process. During the shut off period the radiator icon flashes and then after a short time the pump icon goes off until the boiler starts to fire up again. The wireless thermostat in the hall appears to be calling for heat during all of this.
Is this normal as the radiators cool down a fair bit before the boiler reheats.
I have had the installer back but he said just to turn the CH temperature up and that will sort it.
Any thoughts would be appreciated.

Thanks

 

[mickyg]

poor circulation. If this is a new boiler then your installer should be rectifying this issue but as he hasnt recognised the problem it doesnt fill me with hope.
Was the system flushed prior to the new boiler being fitted?

 

[Tibbot]

There is a time delay built in which will stop the boiler re-firing even if it's required but not enough for rads to noticeably cool or boiler temp to race down. So as already advised, poor circulation, or if from day one, full of trapped air.

 

[phxgs1]

Thanks for that. I will probably try to bleed the sytem first. Not sure about the flush.I had a magnetic filter installed with the boiler.I doubt that this would cause any problem but I will clean it also. Is it posible that the pump is holding some air and maybe not performing as well as it might. If so is it straightforward to bleed.
Again many thanks for you replies.

 

[mickyg]

there's an air vent on top of the pump. the cap on this should be loose. It should be sufficient on its own to vent the pump.

 

[Razor900]

I'd try setting D0 to 14kW or so.

Go for a long slow burn rather than a quick full power one.

 

[phxgs1]

I will bleed the pump and see if things improve. If not then I will bleed the radiators etc. I was wondering if the fact that much of the system is 8mm microbore would cause enough poor circulation to show the problem described. I hope not as it will be a big job to sort all that out.
Once again guys, thanks a lot for your thoughts.