Hi All,

We are building a house with wet underfloor heating which goes back
to 2 control units, which have all the wiring completed, only leaving
2 wires from each unit going back to the boiler (volt free). the
boiler has now been installed (Worcester Greenstar 12/18) which I
could not find any volt free connections, I spoke with Worcester bosch
technical today and all they could tell me was that the boiler doesn`t
have the appropriate connections, but could not tell me how I could
resolve this problem.
Anyone shed any light???.

On Fri, 02 Jan 2009 10:55:10 -0800, yekal_tytwr wrote:

Hi All,

We are building a house with wet underfloor heating which goes back
to 2 control units, which have all the wiring completed, only leaving
2 wires from each unit going back to the boiler (volt free). the
boiler has now been installed (Worcester Greenstar 12/18)

Is that an oil boiler? I don't recognise the model name as a gas one.

... which I
could not find any volt free connections, I spoke with Worcester bosch
technical today and all they could tell me was that the boiler doesn`t
have the appropriate connections, but could not tell me how I could
resolve this problem.
Anyone shed any light???.

Not sure what your UFH control units require. You say they want volt-free
connections but not whether the connection is a signal from the boiler to
the UFH controller or the other way. If the former maybe the UFH
controller has its own mains power for its pump and just needs a contact
closure to tell it to run the pump. In that case I'd be thinking along
the lines of fitting a pipe thermostat to the boiler's flow pipe to tell
the UFH when there's heat coming from the boiler.

Alternatively if the volt-free connection is a signal /from/ the UFH
controller /to/ the boiler from a set of contacts in the controller, then
I'd think along the lines of connecting across the boiler's LS and LR
terminals.

I think you really need to scan and post the UFH instructions somewhere for
us all to see (or point us to the mfr's docs online).



--
John Stumbles -- http://yaph.co.uk

A: Because it messes up the order in which people read text.
Q: Why is top-posting a bad thing?

On Jan 2, 9:21*pm, YAPH wrote:
On Fri, 02 Jan 2009 10:55:10 -0800, yekal_tytwr wrote:
Hi All,

* *We are building a house with wet underfloor heating which goes back
to 2 control units, which have all the wiring completed, only leaving
2 wires from each unit going back to the boiler *(volt free). the
boiler has now been installed (Worcester Greenstar 12/18)

Is that an oil boiler? I don't recognise the model name as a gas one.


Yes this is an oil condensing boiler



... which I
could not find any volt free connections, I spoke with Worcester bosch
technical today and all they could tell me was that the boiler doesn`t
have the appropriate connections, but could not tell me how I could
resolve this problem.
* *Anyone shed any light???.

Not sure what your UFH control units require. You say they want volt-free
connections but not whether the connection is a signal from the boiler to
the UFH controller or the other way. If the former maybe the UFH
controller has its own mains power for its pump and just needs a contact
closure to tell it to run the pump. In that case I'd be thinking along
the lines of fitting a pipe thermostat to the boiler's flow pipe to tell
the UFH when there's heat coming from the boiler.

Alternatively if the volt-free connection is a signal /from/ the UFH
controller /to/ the boiler from a set of contacts in the controller, then
I'd think along the lines of connecting across the boiler's LS and LR
terminals.

I think you really need to scan and post the UFH instructions somewhere for
us all to see (or point us to the mfr's docs online).


thanks for your reply , I can`t work out if it is possible to post the
wiring diagrams on here, would you mind if I email them to you?.



--
John Stumbles *-- *http://yaph.co.uk

A: Because it messes up the order in which people read text.
Q: Why is top-posting a bad thing?

Yekal wrote:
On Jan 2, 9:21 pm, YAPH wrote:
On Fri, 02 Jan 2009 10:55:10 -0800, yekal_tytwr wrote:
Hi All,

We are building a house with wet underfloor heating which goes back
to 2 control units, which have all the wiring completed, only
leaving 2 wires from each unit going back to the boiler (volt
free). the boiler has now been installed (Worcester Greenstar 12/18)

Is that an oil boiler? I don't recognise the model name as a gas one.


Yes this is an oil condensing boiler



... which I
could not find any volt free connections, I spoke with Worcester
bosch technical today and all they could tell me was that the
boiler doesn`t have the appropriate connections, but could not tell
me how I could resolve this problem.
Anyone shed any light???.

Not sure what your UFH control units require. You say they want
volt-free connections but not whether the connection is a signal
from the boiler to the UFH controller or the other way. If the
former maybe the UFH controller has its own mains power for its pump
and just needs a contact closure to tell it to run the pump. In that
case I'd be thinking along
the lines of fitting a pipe thermostat to the boiler's flow pipe to
tell the UFH when there's heat coming from the boiler.

Alternatively if the volt-free connection is a signal /from/ the UFH
controller /to/ the boiler from a set of contacts in the controller,
then I'd think along the lines of connecting across the boiler's LS
and LR terminals.

I think you really need to scan and post the UFH instructions
somewhere for us all to see (or point us to the mfr's docs online).


thanks for your reply , I can`t work out if it is possible to post the
wiring diagrams on here, would you mind if I email them to you?.



--
John Stumbles -- http://yaph.co.uk

A: Because it messes up the order in which people read text.
Q: Why is top-posting a bad thing?

Scan - or photograph the picture[s] using a digital camera and upload them
to www.tinypic.com, give a 'Tag' (or name) and then post the IMG Code for
Forums & Message Boards link to the group. Example below (it works if you
want to view the image):

Note: leave out the [IMG]
either side and post link thus:

http://i44.tinypic.com/25gavxt.jpg - note the coloured and underlined text
that indicates a valid link.


Hope this helps


Cash

On Jan 2, 11:07*pm, "Cash"
wrote:
Yekal wrote:
On Jan 2, 9:21 pm, YAPH wrote:
On Fri, 02 Jan 2009 10:55:10 -0800, yekal_tytwr wrote:
Hi All,

We are building a house with wet underfloor heating which goes back
to 2 control units, which have all the wiring completed, only
leaving 2 wires from each unit going back to the boiler (volt
free). the boiler has now been installed (Worcester Greenstar 12/18)

Is that an oil boiler? I don't recognise the model name as a gas one.

*Yes this is an oil condensing boiler

... which I
could not find any volt free connections, I spoke with Worcester
bosch technical today and all they could tell me was that the
boiler doesn`t have the appropriate connections, but could not tell
me how I could resolve this problem.
Anyone shed any light???.

Not sure what your UFH control units require. You say they want
volt-free connections but not whether the connection is a signal
from the boiler to the UFH controller or the other way. If the
former maybe the UFH controller has its own mains power for its pump
and just needs a contact closure to tell it to run the pump. In that
case I'd be thinking along
the lines of fitting a pipe thermostat to the boiler's flow pipe to
tell the UFH when there's heat coming from the boiler.

Alternatively if the volt-free connection is a signal /from/ the UFH
controller /to/ the boiler from a set of contacts in the controller,
then I'd think along the lines of connecting across the boiler's LS
and LR terminals.

I think you really need to scan and post the UFH instructions
somewhere for us all to see (or point us to the mfr's docs online).

thanks for your reply , I can`t work out if it is possible to post the
wiring diagrams on here, would you *mind if I email them to you?.

--
John Stumbles --http://yaph.co.uk

A: Because it messes up the order in which people read text.
Q: Why is top-posting a bad thing?

Scan - or photograph the picture[s] using a digital camera and upload them
towww.tinypic.com, give a 'Tag' (or name) and then post the IMG Code for
Forums & Message Boards link to the group. *Example below (it works if you
want to view the image):

*Note: leave out the [IMG]
either side and post link thus:

http://i44.tinypic.com/25gavxt.jpg- note the coloured and underlined text
that indicates a valid link.

Hope this helps

Cash- Hide quoted text -

- Show quoted text -

Thanks for all that, I will give it a go fingers crossed!!

http://i40.tinypic.com/2eund40.jpg this one is the boiler wiring
diagram

http://i44.tinypic.com/303e4c7.jpg and this should be heating
diagram

this link has not gone blue as yours hopefully it will appear blue
when I post, well here we go!

On Sat, 03 Jan 2009 11:31:12 -0800, Yekal wrote:

http://i40.tinypic.com/2eund40.jpg this one is the boiler wiring
diagram

http://i44.tinypic.com/303e4c7.jpg and this should be heating
diagram

OK the "boiler relay / volt-free" connection is a pair of contacts which
close when the controller wants the boiler to run. It's "volt-free" because
neither of the contacts is tied to anything of a set voltage, such as
mains live. If you wire that pair of contacts to LR and LS (leaving NS
not connected to anything) then the boiler will fire up when the
controller wants it to. Assuming the boiler has a pump built-in then that
wil run too, without you having to connect anything to the boiler's "pump
relay / voltfree" contacts.



--
John Stumbles -- http://yaph.co.uk

Thank God I'm an atheist

On Jan 3, 9:00*pm, YAPH wrote:
On Sat, 03 Jan 2009 11:31:12 -0800, Yekal wrote:
http://i40.tinypic.com/2eund40.jpg* * this one is the boiler wiring
diagram

http://i44.tinypic.com/303e4c7.jpg* * and this should be heating
diagram

OK the "boiler relay / volt-free" connection is a pair of contacts which
close when the controller wants the boiler to run. It's "volt-free" because
neither of the contacts is tied to anything of a set voltage, such as
mains live. If you wire that pair of contacts to LR and LS (leaving NS
not connected to anything) then the boiler will fire up when the
controller wants it to. Assuming the boiler has a pump built-in then that
wil run too, without you having to connect anything to the boiler's "pump
relay / voltfree" contacts.

--
John Stumbles *-- *http://yaph.co.uk

Thank God I'm an atheist

The boiler does have its own built in pump, and as per one of your
previous posts the heating controls do have their own mains pump.
If i understand this, I just need to connect the L & N from both the
upstairs and downstairs heating controls to LR & LS of X2 on the
boiler, (does it matter which wire goes to which connection?).
Do you think I will be OK using the integral programmer? (which was
purchased seperate and now fitted), or will I need to get an external
one? as last time I spoke with Worcester they seem to think the
integral one won`t work with underfloor heating.

Cheers
Yekal.

On Sat, 03 Jan 2009 14:20:18 -0800, Yekal wrote:

Do you think I will be OK using the integral programmer? (which was
purchased seperate and now fitted), or will I need to get an external
one? as last time I spoke with Worcester they seem to think the
integral one won`t work with underfloor heating.

I think you need to use a timer external to the boiler to control the
heating. From what I saw of your UFH controllers it looks as if they either
have or need to have their own time controls. If you just want the whole
house heating on or off at the same times then you can use one timer. If
you want zones controlled separately e.g. downstairs warm during day,
warmer in evening, practically off at night; upstairs background during
day, warm evening, cool night, warm morning; then I'd use separate
programmable thermostats for the zones.

Is the boiler a combi? If so you don't need a time control for hot water
(unless the boiler has some sort of pre-heat or storage function which can
be switched on & off). If it has, or if it's a conventional non-combi,
then you'll need a time control for that. BTW a "programmer" is
conventionally a device with independent timer controls for heating and
HW in one box.



--
John Stumbles -- http://yaph.co.uk

I can't stand intolerance

YAPH wrote:
On Sat, 03 Jan 2009 14:20:18 -0800, Yekal wrote:

Do you think I will be OK using the integral programmer? (which was
purchased seperate and now fitted), or will I need to get an external
one? as last time I spoke with Worcester they seem to think the
integral one won`t work with underfloor heating.

I think you need to use a timer external to the boiler to control the
heating. From what I saw of your UFH controllers it looks as if they either
have or need to have their own time controls. If you just want the whole
house heating on or off at the same times then you can use one timer. If
you want zones controlled separately e.g. downstairs warm during day,
warmer in evening, practically off at night; upstairs background during
day, warm evening, cool night, warm morning; then I'd use separate
programmable thermostats for the zones.


After calcuating the time constant for my floors, which are screed and
wet UFH with not a huge margin over whats needed in temps like this, I
decide to simply run the thing 24x7 on its own thermostatic circuit.

The overshoot is much less. - about half a degree instead of a degree,
and the heating isn't running as hard as it used to..
To be brutally honest, timing wet screeded UFH is almost a waste of time
in the winter.

Probably far better to simply hard wire it to a thermostat and a switch.



Is the boiler a combi? If so you don't need a time control for hot water
(unless the boiler has some sort of pre-heat or storage function which can
be switched on & off). If it has, or if it's a conventional non-combi,
then you'll need a time control for that. BTW a "programmer" is
conventionally a device with independent timer controls for heating and
HW in one box.

On Jan 6, 11:10*pm, The Natural Philosopher wrote:
YAPH wrote:
On Sat, 03 Jan 2009 14:20:18 -0800, Yekal wrote:

* Do you think I will be OK using the integral programmer? (which was
purchased seperate and now fitted), or will I need to get an external
one? as last time I spoke with Worcester they seem to think the
integral one won`t work withunderfloorheating.

I think you need to use a timer external to the boiler to control the
heating. From what I saw of your UFH controllers it looks as if they either
have or need to have their own time controls. If you just want the whole
house heating on or off at the same times then you can use one timer. If
you want zones controlled separately e.g. downstairs warm during day,
warmer in evening, practically off at night; upstairs background during
day, warm evening, cool night, warm morning; then I'd use separate
programmable thermostats for the zones.

After calcuating the time constant for my floors, which are screed andwetUFH with not a huge margin over whats needed in temps like this, I
decide to simply run the thing 24x7 on its own thermostatic circuit.

The overshoot is much less. - about half a degree instead of a degree,
and the heating isn't running as hard as it used to..
To be brutally honest, timingwetscreeded UFH is almost a waste of time
in the winter.

Probably far better to simply hard wire it to a thermostat and a switch.



Is the boiler a combi? If so you don't need a time control for hot water
(unless the boiler has some sort of pre-heat or storage function which can
be switched on & off). If it has, or if it's a conventional non-combi,
then you'll need a time control for that. BTW a "programmer" is
conventionally a device with independent timer controls for heating and
HW in one box.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Thanks everyone, got everything ready to go, but can`t get delivery of
oil till next week, then I will know if it all works!.

Yekal wrote:
On Jan 6, 11:10 pm, The Natural Philosopher wrote:
YAPH wrote:
On Sat, 03 Jan 2009 14:20:18 -0800, Yekal wrote:
Do you think I will be OK using the integral programmer? (which was
purchased seperate and now fitted), or will I need to get an external
one? as last time I spoke with Worcester they seem to think the
integral one won`t work withunderfloorheating.
I think you need to use a timer external to the boiler to control the
heating. From what I saw of your UFH controllers it looks as if they either
have or need to have their own time controls. If you just want the whole
house heating on or off at the same times then you can use one timer. If
you want zones controlled separately e.g. downstairs warm during day,
warmer in evening, practically off at night; upstairs background during
day, warm evening, cool night, warm morning; then I'd use separate
programmable thermostats for the zones.
After calcuating the time constant for my floors, which are screed andwetUFH with not a huge margin over whats needed in temps like this, I
decide to simply run the thing 24x7 on its own thermostatic circuit.

The overshoot is much less. - about half a degree instead of a degree,
and the heating isn't running as hard as it used to..
To be brutally honest, timingwetscreeded UFH is almost a waste of time
in the winter.

Probably far better to simply hard wire it to a thermostat and a switch.



Is the boiler a combi? If so you don't need a time control for hot water
(unless the boiler has some sort of pre-heat or storage function which can
be switched on & off). If it has, or if it's a conventional non-combi,
then you'll need a time control for that. BTW a "programmer" is
conventionally a device with independent timer controls for heating and
HW in one box.- Hide quoted text -
- Show quoted text -- Hide quoted text -

- Show quoted text -

Thanks everyone, got everything ready to go, but can`t get delivery of
oil till next week, then I will know if it all works!.

You can tell if the boiler has been running here, by the 4 cats draped
over the pipe runs in the corridor..never did install heating on the
landing above..not needed.