Combi Boiler With 2 Valves/roomstats

[dave2]

Today's job was to make good boiler wiring.

There are 2 roomstats with 2 diverter valves for upstairs and downstairs zones and its a combi.

Its a 2 year old system which has never worked correctly. When calling for heat on downstairs stat both valves open so whole house is heated. The same applies to the upstairs stat! 

Wiring is a total mess but basically the permanent live is connected to the brown wires of the valves hence the valves are open all the time so when any stat calls for heat the whole house gets it.

Anyway got it sorted and now working ok but still not happy.

As its a combi, the boiler has a permanent live so in effect the orange wires of the valves become redundant or am I missing a trick?

Normally with one roomstat I would remove the stat link in the boiler and connect the stat across it, but this cannot be done with 2 roomstats. I've left the link in place and  wired perm. live --stat---brown of valve.

Anyone come across this before?

How did you overcome the problem?

 

[NozSpark]

No... wire the orange wires back to the boiler (Lr on Worcester Greenstars)!

 

[ProDave]

Think it trough logically and rewire it.

Upstairs room stat energises upstairs 2 port valve. 

downstairs room stat energises downstairs 2 port valve.

If there's a time clock, that feeds both thermostats, so thermostats and valves only operate when the time clock says so.

If they are programable stats instead of a timeclock, then each programable stat just operated it's own valve, nothing more, nothing less.

THAT wiring is independent of the boiler.

Then EITHER 2 port valve closing calls for heat from boiler. (boilers thermostat terminals) Orange and grey from both 2 port valves in parallel to the boilers thermostat terminals.

EDIT

I've re phrased it a bit to try and explain it clearer.

 

[dave2]

Thanks guys.

The boiler is a Warmflow 120 HE oil boiler.

Yes the greys and oranges are parallel.

The stats are  battery operated programmable.

 

[NozSpark]

Think about it for a minute....

If it was a single zone system you'd wire the programmer and roomstat back to the boiler terminals.... now add a valve (with a perm live[grey], demand in[brown], neutral [blue] and demand out[orange]) ..... now the orange is the demand control instead of what would have been the room stat demand.

Now you wire the other zone the same with both oranges giving you the heating demand

They will not back feed because they switch in the valve

 

[SLIPSHOD & SLAPDASH]

This is a question for rb surely ?   Oh no, thinking  it through it was possibly him who originally wired it.

 

[dave2]

I today contacted Warmflow  and their advice was to leave the link (5 - 28) in place at the boiler and connect orange wires from valves to 5.

Thanks for all the replies----they were all correct.

 

[Sidewinder]

Thanks dave2 it is nice for a poster to come back & let everyone know that their issue is solved.