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