Drayton ZA5

[bocsta]

I thought my Heating was causing my boiler to fly for short spurts of 5 secs but today after disconnecting the live feed from my Underfloor heating to the boiler, I discovered that the boiler was still firing in short spurts with only the HW wiring connected.

But the HW control was set to off, thermostat down to lowest and zone valve closed. I watched the boiler fire up every 7 mins or so for 5 secs when nothing was demanding.

If it is the actuator microswitch (got no multimeter at mo...at mates), what else is happening water wise when the boiler fires continually in short spurts and the valve is closed. Does this have any effect on pressure ?

 

[D_Hailsham]

Where is the boiler located?

 

[Dan Robinson]

and what the f* is it?

 

[doitall]

Make and models may be a good plan as well, especially the boiler.

 

[bocsta]

Keston Celsius 25

I think it must be the microswitch as the actuator lever is in the off position yet the boiler is still being called

The valve doesnt look to be sticking as its moveable by hand so its staying closed

But is this common with the ZA5 actuators ?

Couldnt see much of the microswitch when I took the actuator cover off but the Drayton literature says "A micro-switch is fitted inside the actuator which makes contact when the valve is fully open. The auxiliary (or end) switch is used to switch boilers, pumps etc. It is not electrically connected to the drive motor."

So if its not electrically connected and therefore mechanical, how can it be switching if the valve is closed ?

 

[doitall]

Perhaps the micro switch is stuck, or someone wired it up wrong.

 

[bocsta]

picked up a new ZA5 actuator today...will be going on tomorrow/Sat and th old one going under the knife!

 

[bocsta]

New ZA5 on ...all good

old microswitch is a sealed unit so without meter cant tell if it was the culprit