radiators on all the time

[task]

Hi everyone
could anyone please help I have a gravity fed central heating system about 14yrs old.
the boiler is a myson orion.
I have instaled a new pump and a 3 way valve.
when the hot water is turned on it works fine,with the room stat at 0 deg i then put the heating on,
that works fine as it does not go on till i move the room stat to 25deg and the 3way valve operates.
when i turn down the room stat the 3way valve does not close and when i turn off the heating only the 3way valve does not close.
that means the heating is on all the time
is the 3way valve faulty ?
the roomstat faulty ?
or the control unit faulty ?
can anyone please advise me if there is a way to test these
have a good x-mas to you all task.......

 

[weareleeds]

First of all you ain't got a gravity system. When you have a 3 way valve & the last thing used was htg only then the valve stays powered via the grey wire if you put demand for hot water only does it spring back

 

[JohnD]

Do you mean it was installed as a gravity system, and you later fitted a pump and 3-way?

Did it ever work right, or might you hav made a mistake with the fitting?

Instead of asking here if the room stat is faulty, you ought to be testing it with a meter; first at the thermostat, then wherever it connects to. I'd be looking at the operation of the 3-way first, if I were you, like weareleeds says.

 

[task]

First of all you ain't got a gravity system. When you have a 3 way valve & the last thing used was htg only then the valve stays powered via the grey wire if you put demand for hot water only does it spring back

no it does not spring back,when i first installed it,it worked fine and you could move it manually very easily,now it is harder to move and does not return.
when i remove the motor body the valve is easy to move again.
do you think the motor has failed?
the unit fitted is a SIEMENS LANDIS AND STAEFA MA-V322C
CHEERS FOR THE HELP
merry x-mas TASK.....

 

[task]

First of all you ain't got a gravity system. When you have a 3 way valve & the last thing used was htg only then the valve stays powered via the grey wire if you put demand for hot water only does it spring back

no it does not spring back,when i first installed it,it worked fine and you could move it manually very easily,now it is harder to move and does not return.
when i remove the motor body the valve is easy to move again.
do you think the motor has failed?
the unit fitted is a SIEMENS LANDIS AND STAEFA MA-V322C
CHEERS FOR THE HELP
merry x-mas TASK.....

Cheers for the help everyone nearly blew myself up, now the 3 way valve is working fine there is a god task