Discuss Central heating problems as programmer not bring on boiler fixed in the Central Heating Systems area at ElectriciansForums.net

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Xcody

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A client has decided to attempt a dual programmer replacement and made a mess, i have reconnect everything as following but the boiler and programmer arent working together, just wondering if any one would have a look at the connections to see if i missed something or if they have another idea about issue, we have a Drayton dual programmer with a Drayton room thermostat
Connections to programmer as flows LNE from switched fuse, i then have the core from the room stat that calls for heat on to the CH on terminal of the programmer, the feed to the room stat is joined in a connector with the a core that runs out to the boiler (connected to one of the room stat terminal at boiler) i then have another core to do with the room stat that comes from the boiler connected to CH off on the programmer
As i do not do a lot of this line of work am just seeking advice thanks
 
Hard to tell..
Sounds like a Combi boiler from the vague description but who knows? You haven't mention anything to do with HW so I'm taking a guess.

We need Boiler information and a drawing really.

Just to be aware.. If it is a Combi then is worth investigating properly different boiler manufacturers have different ideas. Some makes of boilers like to make roomstat controls volt free. Most dual channel programmers send out 230v to CH and HW termnials so be careful you don't blow up the boiler
 
Not sure what the ch off is doing, don't think it is required.
Ch on to room stat as you show, then to boiler (terminal usually market rt) - the switched live return. Often there is a link which needs to be removed when using external controls
 
So it's a Combi or a Y plan ?
Looks like a Combi to me..

You need to go into "common" then CH on terminals of the Programmer.

You probably haven't got a common terminal on your Programmar though because on 2 CH programmers it' usually linked internally to the perm Live.
That's why it's important you check that the room stat terminals take a voltage.

Why not use a single Channel Programmer if it' a Combi ?

Verify its a combi first if so, put a link between the stat terminals on the boiler to make sure the boiler still works and you haven't stuck a voltage through volt free connections.
 
FS terminal on the boiler to Common on the Programmer
FR terminal on the boiler to Call for Heat on Stat
CH ON on Programmer to L on Stat

If no Common on the Programmer, take FS from Boiler to L on Programmer and put the Perm Live current there into a choc block or the like.
 
Have you measured at the stat to make sure the programmer is providing 240V? If yes, when the stat is calling is there 240v on the stat terminal connected to the boiler? If yes then the stat is either connected to an incorrect terminal on the boiler (or links required / removed) or their is a problem with the boiler pcb
 
If it's a y-plan then your drawing is completely wrong as CH on would go to common of the room thermostat, switched live from thermostat would go to white of the 3port valve, orange of the 3port valve would connect to LR on boiler. All external controls should be fed from LS so they are protected by the boilers internal fuse and in accordance with the manufacturers instructions. If it is a Y-plan with an unvented cylinder then the boiler will probably be a system boiler and not a combi.

You should have HW on from the programmer connected to the common of cylinder thermostat, normally closed on cylinder thermostat will connect with grey on 3 port and HW off on programmer. Normally open on cylinder thermostat will connect with orange of 3 port and LR on boiler.
 
The thermostat connection on the boiler may be low voltage with one leg of the control supply grounded. If this is the case, connecting a neutral at the stat may be causing a problem. I would suggest removing the neutral from the stat and try it again.
 
The thermostat connection on the boiler may be low voltage with one leg of the control supply grounded. If this is the case, connecting a neutral at the stat may be causing a problem. I would suggest removing the neutral from the stat and try it again.
The op states it's a Worcester Bosch green star boiler. The thermostat connections on these are 230V not ElV or Volt free. LS provides 230V out for controls and LR is live return.
 

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