No hot water

[alan15]

Hi
Having a bit of a problem at the moment. Have a honeywell Y plan system. First of all the temp of the water at the taps started to get to hot and then there was no hot water, so i changed the thermostat on the cylinder, it then worked for one night and packed up again. I checked some voltages and found i had no voltage on the orange wire from 3 port valve which fires up pump and boiler (System was calling for hot water). I felt the motor of the 3 port valve and it was red hot although all pipework was cold. Changed the head of 3 port valve and system fired up straight away, worked that evening and in the morning but then packed up again. Could it be the programmer? The radiator side of things works fine.
Any help would be great as i'm lost.

 

[seco services]

I checked some voltages and found i had no voltage on the orange wire from 3 port valve which fires up pump and boiler (System was calling for hot water).

the 230v won't come from the valve/orange it'll come from the cylinder stat.
it's just that the cyl stat call is in the same terminal as the orange.

I felt the motor of the 3 port valve and it was red hot although all pipework was cold.

more likely being held in last position from ie the heating being on.
will be held in last position by the grey wire.

Changed the head of 3 port valve and system fired up straight away, worked that evening and in the morning but then packed up again. Could it be the programmer? The radiator side of things works fine.
Any help would be great as i'm lost.

can't see how it worked by changing the 3 port as hw has nothing to do with the valve

only by giving the grey 230v from the programmer/cyl stat satisfied/off.

 

[alan15]

if i had 240v on the grey and the orange at the same time at the terminal centre what could that be

 

[seco services]

240v on the grey is hw off at programmer or on at programmer but satisfied at cyl stat.

240v on orange terminal if no power on the white wire [heating call]
the i would say thats 240v from the hw stat calling as that wire is in the same terminal with the orange.

quite poss your programmer is giving out 240v on hw calling and also hw off.

check the programmer wires.
whats giving the grey power - wire from stat or programmer ?
whats giving the orange terminal power - power on the white ? power from the cyl stat ?


make sure heatings off at programmer.
hw calling at programmer cyl stat up.

should be power from cyl stat wire in orange terminal block.
nothing on grey.
lever on 3 port should have resistance.

 

[alan15]

thanks for that. I can say that there is no resistance on the lever of 3 port valve

 

[seco services]

thanks for that. I can say that there is no resistance on the lever of 3 port valve

then the heatings been on and that was last port of call.
to get the 3 port back to hw open heating closed and resistance on the lever you can isolate your fused spur and turn back on that will set the valve back in relaxed position.

 

[alan15]

thanks for your help i will check this all out tomorrow