worcester 18 ri boiler turns on when it wants

[mikeyc1]

Hi hope someone can help my worcester 18 ri boiler is now 18 months old and has started to come on when it wants even when the programmer is off and the room stat is turned right down,it fires up and the radiators come on,the only way to turn it off is to turn the thermostat/reset knob on the front of the boiler (right hand knob) to low,any advice would be appreciated just so when i get it looked at next week i have some idea what the fault might be,many thanks for your time.

 

[45yearsagasman]

Got any of these? View media item 30391 View media item 38425

 

[mikeyc1]

Hi yes i have a three way valve in my system

 

[oph]

Residual voltage feedback from the motorised valve down the switch live cable back to the LR terminal on the boiler I would think thus causing demand

 

[simond]

This doesn't tend to affect newer products like the 18Ri. Was the case with earlier pre 2005 certain models.

 

[mikeyc1]

Hi as i sit here worrying about my boiler i have just noticed that since my hot water has come on and is now off, and my heating is now on for the evening the boiler is now acting normally and is now controlled by the room stat,the thermostat/reset knob now has no effect regarding turning the boiler on or off.Does this info give you any more thoughts on my problem,many thanks again for your time.mike.

 

[Agile]

I would start by measuring/monitoring the call for heat connection to the boiler.

The residual voltage problem can usually be cured by adding a resister of about 68K between SWL and Neutral. Must be about 1 watt though.

Tony

 

[mikeyc1]

Hi thanks for the info will let you know the outcome when it is looked at this week.