My LG gas range (LRG3095S) has started to have preheating problems. The temperature on display appears to rise very slowly, and sometimes the oven stops preheating with an 'F11 heat error'. I don't believe there is any issue with the gas supply. While trying a preheat to 400 I found that the temperature was "stuck" at 200 for a while, not rising. I canceled and then immediately restarted a preheat to 400, and the panel displayed 270. I trying to get some insight as to whether this is a sensor or control board issue. Thanks.