my ch wont turn off by the timer

[cassjag]

when i first start up the heating it will switch on & off via the timer buttons but at the end of the day will not switch off by the timer (in fact the switched live is still sending a signal even though no lights are displayed),
i keep hearing about motorised valves, yes it is a "s"plan but why would they be able to send a signal through the switched live? can anyone tell me how to check? i think it may be a relay in timer siezing.
thanks for any help i can get.
Cass

 

[seco services]

the only wire that is live on zone valves when the programmer is off should be the grey.

check the brown isn't live from the stats. if no live on brown but the orange is still live then the micro switch is stuck inside the valve.
the orange becomes live when the m/switch is operated and the live comes from the grey.

live on the brown from the stats only operates the motor.

 

[cassjag]

ok ill check tomorrow but i still cant get my head round why it switches on & off by the button earlier on, is this something that you have come across before? are the valve switches easy to replace?

 

[seco services]

ok ill check tomorrow but i still cant get my head round why it switches on & off by the button earlier on,

could also be the spindle sticking holding it open.
may only be sticking if its been in the on position for a long period like alday.

checking the voltages will tell you the answer.

are the valve switches easy to replace?

people have changed them before but it's not cost effective for us to waste a day doing it cheaper/easier to fit a new valve and be in/out of the customers house.

you can obtain them from maplins.

 

[cassjag]

thanks for that advice i'll check voltages, the heating is on all day so i will also bang it back onto three times to give it a couple of rest's to see if that helps. once again cheers for the advice.
cass

 

[cassjag]

your advice was spot on it was the motorised valve, i have changed that now but i had to drain the system but now my downstairs rads wont heat up

 

[twgas]

You've probably got an air lock, turn off the HW and the upstairs rads and see if that helps, when a downstairs rad gets hot turn it off and on to the next one.

 

[cassjag]

the rads still not getting very hot at the bottom this has got me quite confused as it was fine yesterday before i drained it