Optima 700 heating problems

[alexbetts]

Hi all.

This optima 700 will fire up for dhw but not heating. Fan is working, pump is working aps obviously working otherwise wouldn't light for dhw I linked out the clock still no luck. Have advised they weigh it in but there skint.

 

[MANDATE]

Sounds like a motorised valve problem. a faulty motor (valve not moving) or faulty micro switches (switch not be triggered or dirty contacts preventing power output from valve to light boiler)