Flow- Vent- Feed -Pump

[desktop987456]

If you're installing a programmer then that's different again

No zone valve for this heat only set up. You are right, I had a 3 port valve with the package but I have separate HW arrangement for now.

Wanted to use programmer as a timer switch only to put heating on at set times of the day.

I agree no compromise on safety, will follow safe practices for wiring installation.

 

[fixitflav]

It has N,L and 3 which is call for heat. Things are making sense and clearing up for me! So for Thermostat to work, the link between 1 and L has to be removed.
With Therm Stat out of the way, programmer doesn't need to get N,L from boiler? Does a SL or other cables need to go to Thermostat?

When you installed the link between L and 1, am I right in thinking there were no external wires connected to the G terminals? That would mean L gets 230 volt from inside the boiler, and a roomstat would be connected between L and 1, and the link removed.
If using a programmer (as your attachment) CH on from the programmer to the roomstat, switched live from the roomstat to G 1 on the boiler. No need for an external 230 volt to G L.

 

[Madrab]

Wanted to use programmer as a timer switch only to put heating on at set times of the day.

The programmer would be powered via the wiring centre (have all CH systems and accessories powered from the same FCU) and then as suggested above - the 230v switching to the boiler would come from the programmers internal connection via CH on, through the stat - L (live in) > 3 (switched out) - then from stat 3 (SL out) > boiler 1(SL in)

 

[desktop987456]

am I right in thinking there were no external wires connected to the G terminals

Correct. Just the capacitor connected to 1 and N terminals (G)

If using a programmer (as your attachment) CH on from the programmer to the roomstat, switched live from the roomstat to G 1 on the boiler. No need for an external 230 volt to G L.

See attached schematics; a marked and unmarked version. I have attached un marked for corrections (if any)

 

[desktop987456]

The programmer would be powered via the wiring centre (have all CH systems and accessories powered from the same FCU) and then as suggested above - the 230v switching to the boiler would come from the programmers internal connection via CH on, through the stat - L (live in) > 3 (switched out) - then from stat 3 (SL out) > boiler 1(SL in)

sorry, our posts crossed.
So programmer gets N,L from wiring center to turn the heating (boiler) on.

 

[fixitflav]

Correct. Just the capacitor connected to 1 and N terminals (G)

See attached schematics; a marked and unmarked version. I have attached un marked for corrections (if any)

I don't think that's right. I'll try to mark something up, but in words -
L on the programmer is usually fed from the mains (via an isolator). I suppose it could come from L on boiler G, but not normal IMO. And if it was done that way, it would go from L on boiler G to L on the programmer. As you've shown it the roomstat gets Live when the programmer is not calling.
Fused 3A L, and Call for heat on the roomstat confuse things and shouldn't be there.
4 on the programmer should go to L on the roomstat.
3 on the roomstat should go to 1 on boiler G. Better that way round as roomstats often have a booster heater between 3 and N.
No need for any wire to boiler G L.

 

[desktop987456]

It should be wired this way as per schematic?

 

[fixitflav]

It should be wired this way as per schematic?

That's a lot better! Don't forget to ignore the Fused 3A L and Call for heat on the roomstat.

 

[Madrab]

Never use the earth wire as a SL. You want a different colour or sleeve/tape it differently as a L (brown) or yellow(switched)

 

[desktop987456]

All wiring for thermostat to boiler and pump done, I owe it to Rob and Fixitflav for their efforts and for pump setting to Johntheo

One last glitch, I cannot get over is flame symbol on display, I have reset it a number of times with no luck, it starts and keeps firing at lower rate.

I was thinking of starting a separate thread but do you have any ideas?

I have also received a reply from Viessmann basically saying to notch up the setting on central heating dial to raise flame intensity or level.

The flame level goes up and down in 'serv' mode but not in normal mode. It keeps it to the lowest level.

 

[Madrab]

There is nothing to suggest why the boiler would stay in low fire mode unless either there is a purge stage that keeps the boiler in low fire until complete or it has been range rated down @ min. Does the system temp not get any higher than the 36odd deg? Especially if it fires normally in service mode. Was the system properly vented?

 

[fixitflav]

All wiring for thermostat to boiler and pump done, I owe it to Rob and Fixitflav for their efforts and for pump setting to Johntheo

One last glitch, I cannot get over is flame symbol on display, I have reset it a number of times with no luck, it starts and keeps firing at lower rate.

I don't know whether it will add anything, but I've looked through the MI and some things aren't clear (to me).

A sheet to identify the controls and their functions would be helpful.

It refers to Rated heating output range, but doesn't say how to adjust it. Is this the right-hand knob? Or is that for flow temperature adjustment? If it's for output range, how is the temperature adjusted?
The only reference I can see to the left-hand knob is for changing between NG and LPG. Is that all it's for?

I have also received a reply from Viessmann basically saying to notch up the setting on central heating dial to raise flame intensity or level.

I suppose that means the RH dial. Have you tried that and did it do the trick?

 

[desktop987456]

The only reference I can see to the left-hand knob is for changing between NG and LPG. Is that all it's for?

At least that's what the manual says. It doesn't say much on how to change configuration etc. The documentation on getting into settings or configuration menu is very poor. I don't even know how to change units from Deg C to Deg F.

suppose that means the RH dial. Have you tried that and did it do the trick?

Yes, I have tried that repeatedly with no luck. The dial works as it should in Serv mode only, if you notch the level up the flame intensity goes up and down depending on which way you turn it.

 

[desktop987456]

or it has been range rated down @ min

I am not sure if I have done something with the settings but even if I did that, I cannot go to that setting again!

As I have said the temperature or flow temp goes up but very slowly, in Serv mode it does heat up well since it runs in high flame mode.

 

[fixitflav]

At least that's what the manual says. It doesn't say much on how to change configuration etc. The documentation on getting into settings or configuration menu is very poor. I don't even know how to change units from Deg C to Deg F.

Yes, I have tried that repeatedly with no luck. The dial works as it should in Serv mode only, if you notch the level up the flame intensity goes up and down depending on which way you turn it.

Does the RH knob vary the output or the temperature, do you know?