Baxi combi 80eco. Pump problem ?

[Kenny456]

Sometimes we only use one radiator, it gets hot ok, but I have noticed that the pump in the boiler runs all the time, even when the burner is not ignited. Is this normal, I would have thought that because there is not a big demand on the system, ie only one rad, that it would stop sometime.
Any ideas anyone.

 

[Slugbabydotcom]

Generally speaking a pump will run in an 'over run' function either for a set time after the burner switches off OR until a certain boiler temperature is reached. Sometimes this function can be adjusted by altering dip switches on the PCB.
For a specific answer you will have to read the manufacturers instructions. Feel free to post back the specific answer when you find it for the benefit of others with the same question

 

[namsag]

Providing your clock and roomstat are demanding heat then your pump will continue to run no mattter how many or how hot your rads have got and whether the boiler is firing at the time.
It can also continue to run for approx ten minutes after demand has gone

 

[baxpoti]

It can also continue to run for approx ten minutes after demand has gone

No it can't (eco has no pump overrun)

 

[Kenny456]

Many thanks for the quick replies, I understand it better now, it makes sense that the pump will run as long as clock and stat are demanding heat.
There are 4 pots on the circuit board 2 are for the c/h and dhw temperature knobs, are the other 2 anything to do with run time for the pump or fan, I wonder..

 

[baxpoti]

the other 2 anything to do with run time for the pump or fan, I wonder..

MAX. R. is for C/H ouput adjustment and MIN.G. is for minimum power electronic control

 

[Agile]

What do you usually set the gas valve min and the pot min to?

1.5 and 2.5 or something different?

Tony

 

[baxpoti]

Min to max (fully clockwise on PCB and fully wound out on the valve) will give you approx 1.9mbar.

 

[Kenny456]

Cheers baxpoti you know your stuff. but you lost me a bit there. so in laymans terms when I turn Max. R. and Min.G. what exactly will each one do. Regards Kenny456

 

[Agile]

I hope that he will not tell you as these are gas engineers settings.

What you should do though is to turn the Max R to minimum and then up about a quarter unless you live in a big place.

Nice films tonight on Sky 328.

Tony

 

[baxpoti]

If you only run a few rads turn MAX. R. to minimum, this lowers the c/h output.
Normal 3 bed semi needs about 12Kw heat input. You have a 24Kw boiler.

Min.G. is for trimming the minimum setting.

 

[Kenny456]

Many thanks Baxpoti and Agile for taking the time to reply. Ive a much better idea of what to do now, as for watching Films on Sky 328 Agile, Im far to busy twiddling pots. Cheers again guys.
Kenny 456.