Y plan with 2 port twisting my melons man

[stidge]

Hi all, some help please. Wiring boiler on y plan (new Drayton mid pos) and an old Honeywell 2 port. Hot water works fine ( through dual stat).cannot get boiler to fire on heating, checked room stat, mid pos opening but on orange sw/l to boiler only getting 60-68 volts so obviously boiler not firing, have double checked all connections and been there far too long !!!!!! Any suggestions much appreciated cheers

 

[Andyfm]

I have only ever wired three port valves on their own, they can`t be on a system with a two port valve, can they?

 

[stidge]

Yes mate for unvented cylinders to stop overheating I think

 

[stidge]

Had another thought , do I need to wire in the he off from programmer to mid pos valve ?

 

[stidge]

Sorry hw off

 

[Justin2211]

Hi all, some help please. Wiring boiler on y plan (new Drayton mid pos) and an old Honeywell 2 port. Hot water works fine ( through dual stat).cannot get boiler to fire on heating, checked room stat, mid pos opening but on orange sw/l to boiler only getting 60-68 volts so obviously boiler not firing, have double checked all connections and been there far too long !!!!!! Any suggestions much appreciated cheers

hi is the two port a safety valve ie hot hw over heat, also which programer are you using

 

[Justin2211]

I have only ever wired three port valves on their own, they can`t be on a system with a two port valve, can they?

yes you do mate

 

[stidge]

Is this to do with a resistor in motor reducing voltage?

 

[stidge]

Hi justin I believe the 2 port is a safety valve, can't remember programmer name baxos or something ? With this system do I need to wire hw off from programmer

 

[RichardMoore]

The hot water 2 port needs to open first when the clock is on then that will fire the boiler, the the oranges from both the 2port valve and 3 port need doubling up. Also white on the 3port is SL for the heating. I've wired hundreds of heating and now them inside out. If you still struggling ill do a diagram and just wire it to that all clock back are pretty universal in terms of connections on back plates

 

[Justin2211]

Hi justin I believe the 2 port is a safety valve, can't remember programmer name baxos or something ? With this system do I need to wire hw off from programmer

if it is a y plan then yes providing the 2 port is a safety, the voltage part its a back feed as with out hot water off to the 3 port the motor stays where it was last unless its sprung return

 

[Justin2211]

The hot water 2 port needs to open first when the clock is on then that will fire the boiler

with the overheat in-between these of course

 

[stidge]

That's great Richard , if you wouldn't mind doing me a quick diagram.think I just have 1 or 2 crossed, the two oranges are doubled up for sw/l but the white I have coming from room stat call !!

 

[RichardMoore]

Hi pal I've got a diagram from the ozoho****er.co.uk to put on but I cannt seem to post it.sorry. if you google ozo wiring diagram PDF it'll lead you to it that's the one I've memorized. I'm on my iPhone so no idea how to post pics. Hope this helps nothing better than sorting a heating wiring fault out

 

[RichardMoore]

Ozo hot water . Co. Uk

 

[RichardMoore]

The hot water 2 port needs to open first when the clock is on then that will fire the boiler

with the overheat in-between these of course[/QUOTE

Do you mean the cylinder stat in between as if it fails the two port will not open and thus no hot water, safety cut off

 

[stidge]

Cheers Richard will try and find it now thanks again

 

[Justin2211]

with the overheat in-between these of course[/QUOTE

Do you mean the cylinder stat in between as if it fails the two port will not open and thus no hot water, safety cut off

No I mean safety overheat its a secondary stat basically if the cylinder stat fail this will then trip on over heat shutting the valve stopping the cylinder becoming a bomb
This is to stop if for instance the cylinder stat got jammed to call the over heat would trip shutting the valve if that makes sense lol

 

[stidge]

Update- been this morning, added HW off from programmer to wiring centre ! All works fine now with dual stat shutting off 2 port when up to temperature...many thanks to Justin and Richard