Keston C36 Combi boiler - Thermostat no talking to boiler

[mkh278]

Hello All,

I have Keston C36 Combi boiler, installed in 2006, fully services (last one done in Jun 2013). Currently having an issue, being that when thermostat clicks on and off the central heating is still on. "Summer" button works fine, so I am using this function to turn CH on and off (rather then the thermostat). Called on engineer, which wasn't helpful. Then the boiler seems fixed itself somehow, and for some time the "Click on and off" worked on boiler for couple of weeks. Now the issue repeated and I am using "Summer" option for ime being. Hesitant to call for an engineer as never had a good experience with them.

Would any forum-users have any advice on this matter. I am thinking perhaps there are some settings I need to change, becase on the occassion when the boiler "fixed itself", the "t99" message was displayed and we left the boiler on, then it made some noices etc and after that it started working.

I would appreciate any advice on the matter.

 

[mkh278]

No takers? Any advice would be appreciated

 

[JBPHS]

When you pressed the "Summer" button, you have put it into test mode by holding in the button. This is a function for engineers "t99" is the service mode at full rate. This needs to be turned off in normal use so it shows the heating flow temp for heating, or the water temp for hot water use. Pressing the "Reset" will be your easiest way to turn off the test mode if it shows again. If I'm correct, "t99" should clear after 10 minutes ish.

In future, if you are going to use the "Summer" button, a brief press will suffice, do not hold it in. I know these fascias and buttons can wear easily so it would be worth getting someone to check your external controls and the boiler if the problem persists.

James.

 

[mkh278]

Thank you James. Do you think running the test mode (t99 for 10ish minutes) could resolve CH automatic on and off? I.e. Could it be that CH is not automatically turning on and off due to some settings mismatch?

Thanks