Froling S3 Turbo -odd behaviour since pump replacement

[Stig]

Hi, just joined to see if anyone has experience of controller issues with the Froling S3 Turbo.
A bit of background:
The boiler is in a holiday home in France we bought 5 years ago, it was apparently installed in 2014. I have no previous experience with biomass boilers. It was working fine (once I found a manual in English online!) until last September when the circulation (radiators) pump failed and tripped the whole house electrics when it started. We found a suitable Wilus replacement and fitted it in June, tested it with a separate power lead and all seemed OK but it was a bit warm to be firing up the boiler. Jump to last week (I'm only there a couple of times a year) and I fired it up and it heated up the thermal store/accumulator/big water tank but wouldn't run the pump. When I powered the pump independently it then turned the flow temperature down to minimum -not helpful!
I know it can run the pump as the pump's display lights up briefly when the system is first powered on, it also ran it briefly once when I was paging through all the menu setting to see what was going on.
I'm no longer at the house but I did go through photographing every menu page on the display.
Getting someone out to look at it will be inconvenient as I'm not planning to go out again until the spring (I live in the UK), my sister lives 70km away but isn't that technically minded. The house is up in the Vercors mountains so getting trades to travel there can be an issue sometimes.

I'm hoping the collective wisdom here can help me diagnose the issue!

 

[OffGridICF]

Your post in the German Froling forum has gotten a lot of good responses. As posted there, the boiler needs to meet a number of conditions before it will start the circulator to the radiators.

I do not use the boiler to control my heating circuits, but it would make sense for the boiler to turn down the radiator mixer temperature to minimum if the boiler did not turn on the circulator. Once the circulator is started by the boiler it will probably gradually increase the mixer output temperature until it reaches the desired value. If the mixer was set too hot without the circulator running then it might overheat that heating circuit when the circulator starts. The boiler also can't know the actual mixer output temperature unless the water is flowing.

I would check the list of gating conditions from @Holzheizer12345:

-) Radiator pump is allowed to run, when boiler temperature is above X °C
-) Outside temperature X °C, under which the radiator pump is turning on
-) Radiator pump turns off, if radiator temperature is less than X °C
-) Minimum radiator temperature

He did not mention that if you use the Froling to heat your domestic hot water there is a priority setting. If the heating circuit (radiators) priority is set to NO then it will be disabled until the domestic hot water demand is satisfied.

There are also programs that control the heating based on the time of day.

You can download the latest service manual here:
https://www.froeling.com/wp-json/froeling/v1/docs/4518

This is for the latest firmware version but many of the settings are similar in older versions. It will have all the setting options, default operating temperatures, etc. The code needed to enter service mode to see all the settings is not posted in the forums since that might prompt them to change it but you can easily find it with an online search.