Worcester Boiler Problem

[danfoss01]

Hi Folks,
I am having a bit of trouble with a Worcester Bosch 50/70 OOO boiler in that it sometimes does not switch off at the last OFF time,and keeps heating the water etc
Other random things happening include the boiler starting,but not igniting or heating the water - it needs switched off at the mains to stop it,and i also noticed the water pump mad hot at 1500hrs one day - this was after the heating went off at 0800hrs and wasn't due back on until 1700hrs.

I had both Danfoss motorised valve actuators checked and both are working correctly.
There was a slight stiffness in one of the zone port valve 'spindles' (that the actuator attaches to) and the plumber gave it a few turns to loosen it up but the problem is still occuring.

I have also replaced the Horstmann H27 XL programmer with the newer series 2 model.

Before i get someone out to replace the port valves i wondered would it be ok to try a spray of WD40 on the port valve 'spindle' to see if that would help free it up a bit more (if indeed it is sticking and causing the problem)

Any ides anyone?

 

[danfoss01]

Ooops! Just noticed the sticky which says NOT WD40 - will try a suitable lubricant

 

[Agile]

WD40 is fine on motor valve shafts !

But NOT on boiler fans!

 

[simond]

Doesn't sound like a boiler problem to me. if the spindle is stiff on the MV you know what to do. Change the body.

 

[danfoss01]

Doesn't sound like a boiler problem to me. if the spindle is stiff on the MV you know what to do. Change the body.

Yeah - thanks,i'm hoping that will solve the problem.