No Central Heating without Hot Water

[spitbuilder]

System:
Glow worm Hideaway Boiler (fairly ancient)
3 way valve Honeywell V4073A (Brand new)
Controller TH-0471 (No temp control) (Brand new)
Roomstat Danfoss TP5 (2yrs old)
Cylinder stat Honeywell L641A (Brand new)

My previous controller was a Randall 3060 which I have just replaced so that I could have independent control of HW and CH. Since I replaced it I still don't have independent control. I cannot get CH unless I have HW selected too. When CH alone was selected I was not getting a live on the orange wire from the 3 Way valve to the boiler so I fitted a new complete 3 way valve. Still the same! The boiler will not fire up on CH unless I select HW too. The 3 way valve appears to move to all the right places at the right time but it is not firing up the boiler. I have checked the wiring until I see wires in my sleep. It can't be 2 duff 3 way valves can it?
Barry

 

[gas4you]

Sounds like you have not got the programmer wired correctly, ie the DHW off terminal doesn't sound connected, or connected in the right place.

DHW off goes to terminal 7, then grey from 3 port valve goes to 7 and 2 from cyl stat does as well.

 

[namsag]

AS D ave says make sure you have a HW off wire from the clock and an HW satisfied wire (off) from cylinder stat other wise heating will not come on properly

 

[spitbuilder]

Thanks gents. I think you are right. I have been working from an old Honeywell wiring diagram that doesn't have that wire because it is a diagram using a Randall 3060 which did not have an option of CH without HW. The wire you mentioned is missing.
If putting the wire in doesn't fix it I will let you know, but I bet it will.
Thanks a lot,
Barry

 

[spitbuilder]

It works fine. Thanks a lot.
Barry

 

[coalfield]

Boiler - Baxi Solo HE (gravity system)
Honeywell ST9400C1000
Honeywell T6360 termostat
Honeywell V4073A1054 3 Position diverter valve


Sorry to rehash an old thread, but i have exactly the same problem in my new home. It I turn on CH, there is no power to the boiler unless I also turn on HW. HW on its own works fine.

I have a Honeywell ST9400C1000 and can see that both 1 & 2 (HW and CH OFF) are not connected. Additionally I can see that 2 wires (yellow) have been jumped with a connector block, and there is a single blue wire not connected.

Presumably all the correct wiring is there, however how could I identify the correct ones to connect up?

Photos attached! Please Help

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• coalfield
• 7 Aug 2013
• 1

Untitled

• coalfield
• 7 Aug 2013
• 1

Untitled

• coalfield
• 7 Aug 2013
• 1

 

[45yearsagasman]

Have you checked that there is power to the synchron motor in the valve, and if there is, that the motor has not failed?

 

[coalfield]

Have you checked that there is power to the synchron motor in the valve, and if there is, that the motor has not failed?

funnily enough this valve has just been changed as it went faulty. It was in fact this that made me realise that it was not wired correctly as only the heating was working and the water cold. Up until this point I did not think that was possible as the current wiring did not allow it!

I therefore know this part is not faulty...

 

[bellairaphon]

You have wires in ch on hw on but no wire in hw off. Means your valve will sit mid position. And will only shut off when the stat is satisfied presuming its wired correctly upstairs.

Nathan

 

[coalfield]

You have wires in ch on hw on but no wire in hw off. Means your valve will sit mid position. And will only shut off when the stat is satisfied presuming its wired correctly upstairs.

Nathan

In the manual it shows a wiring diagram for Y-plan and s-plan. I presume I should have it wired for Y-plan with the parts I have? I take it there is no easy way to identify if its simply a wire which needs pluging in without working through the whole house wiring . I was hoping it may be one of the loose wires.

 

[bellairaphon]

Yes should be y plan. If you can identify the wired in the wiring centre then you should not have a problem.

Nathan

 

[Agile]

You may or may not have enough wires.

The only way I know to find out is to trace all the wires and see.

That's time consuming and particularly when all the items are not in the same room!

Tony

 

[coalfield]

Thanks for your help. Looks like I will have the task of running up and downstairs tracing wires. From some lunchtime research, my biggest concern now of that my cylinder stat is built in and i think it only has 2 wires. Oh and the little task of trying to get an extra wire linked up! Watch this space!

 

[Agile]

It is possible to add a relay if there are only two wires on the cyl stat.

Tony

 

[coalfield]

the cylinder stat in fact did have 3 wires. Managed to fix bit identifying the point correct terminal and using an unused blue wire (in the pic). Connected up and thankfully working without a hitch.

Now just need to try to stop the gurgling noise...