[OpenTRV-interest] Potential bug with Remote Call For Heat

gary.gladman at talktalk.net gary.gladman at talktalk.net
Sun May 10 07:49:49 BST 2015


Hi

I have been monitoring RCfH and noticed that the boiler would continue though the valve was below the Minimum Valve PC Really Open (10% - default).

I noticed the following code and think it might be the cause ...

OpenTRV\Arduino\V0p2_Main\FHT8V_Wireless_Rad_Valve.cpp:
      
      // Potentially accept as call for heat only if command is 0x26 (38) and value open enough as used by OpenTRV to TX.
      if((0x26 == command.command) && (command.extension >= NominalRadValve.getMinValvePcReallyOpen()))

My understanding is that in the FHT8V protocol the command extension is in the range 0..255 whereas Minimum Valve PC Really Open is loosely 0..100 therefore 10(%) is compared against extension 10  which as a percentage means (10*100/255)  3% hence the boiler is being shut off significantly later than expected and with valves more closed than intended. 

Regards Gary
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