Problem with S Plan central heating sysytem

[Davek33]

Hello, My current system (Glow worm 50e) with danfoss controls has been playing up for a while with various issues. e.g. pump on 24/7, a few radiators are on when heating is switched off at the programmer and some radiators intermittently not working when the heating on, I have rewired it to a standard S plan configuration, my current problem is the boiler now wont fire after rewiring it as per attached diagram, I appear to have a live on pin 10 coming from the boiler even when the boilers front switch is on the off position, is this correct ?. As I think I may have blown the internal pcb when rewiring earlier in the week, I have today due to leaks changed both motorized valves and actuators as the HW actuator was also putting a permanent live on pin 10 due to what I can only assume was from water damage, changing the actuator has resolved the live on pin 10 for this actuator.

http://wiki.diyfaq.org.uk/images/thumb/0/0d/S-Plan-Wiring.gif/512px-S-Plan-Wiring.gif

Any advise greatly recieved.

Dave

 

[picasso]

What wiring configuration did you have before you rewired it to an s plan ?

 

[Davek33]

Hi Picasso, I'm not really sure to be honest there were just loads of small connection choc blocks which was a bit confusing so I decided to purchase a 10 way choc block and wire as per the S diagram etc. my own silly fault not to make a note of how it was.

Dave

 

[TCCHeating]

Deleted: wrong fault finding guide! Give me a minute and ill post the correct one

 

[TCCHeating]

Here you go.

Untitled

• TCCHeating
• 8 Nov 2014
• 2

Untitled

• TCCHeating
• 8 Nov 2014
• 2

Follow this fault finding guide through and you can't fail

 

[picasso]

Your boiler controls the pump (if you have wired it correctly) its probably a fault with the boiler pcb that was causing the pump to run continually, do you have a multimeter ?

 

[Davek33]

Thanks, TCC Heating I'll give that a go tomorrow a.m and let you know how I get on,

Dave

 

[Davek33]

Picasso, since my rewire the pump does not run 24/7 it only comes on when I either I switch the HW or CH switch at the programmer which I believe to be correct operation yes ? and Yes I have a multi meter hence I don't understand why I have 240v output from the boiller when it is switched off at the front of the boiler itself hence this is putting a permanent live to PIN 10. Therefore when I connect it up it makes the pump run constantly. I think the boiler is somehow putting a constant 240 v when it shouldn't be etc.

Dave

 

[TCCHeating]

Pump live and switched live to boiler wired together maybe? That would explain the pump running even when boiler is turned off

 

[picasso]

Then you havent wired it to the boiler correctly the boiler controls the pump and gives pump overrun when the call for heat stops, you have probably wired the pump to the switched live so the pump stops when the call for heat stops, as I said before the pcb is faulty making the pump run 24/7 (when it was wired to the boiler)

 

[Davek33]

TCC Heating my pump live is connected in PIN 10 as is the Live which comes up from my boiler on a three core flex is that incorrect ? I'm sorry not sure what you mean by switched live.

Dave

 

[TCCHeating]

Nope. As picasso said. The pump needs to be connected to the boiler for the pump overrun. It sounds like the boiler doesn't even have a permenant live. Instead of a 3 core cable, you need a 5 core cable going to the boiler from the wireing center:

Permenant live
Neutral
Earth
Switch live (from orange wires on valves)
Pump live (from pump terminal an boiler pcb)

 

[picasso]

Hello can anybody hear me ? is this thing switched on ? hellooooooooo

 

[Davek33]

Thanks Picasso I have two PCB's a small one Part No 202237 which takes the 240 v supply in /3 core flex out and then larger one Part number No 202211 which I assume is the one that controls all including the pump overrun etc.

Dave

 

[picasso]

If you google "s plan with pump overrun" and rewire your controls properly we can then help with any problems you have, its a bit pointless trying to give advice until you have.