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2 boilers, 1 controller
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Jon Connell
May 23, 2013, 3:27:14 AM5/23/13
to
My new house has two boilers heating different parts of the house, but
lousy programmers inconveniently located next to the boilers and no
thermostats. I'd like to be able to control when each of the boilers can
come on as well as have thermostats in each part of the house to
regulate the temperature in those two zones.
I *think* what I need is a 2 zone programmer like this:
http://www.honeywelluk.com/products/Time-Controls/Wired/ST9500C/
Does that sound plausible? The wiring diagrams don't make it clear that
this will control two boilers; they're using different motorized valves
for the two zones.
Jon
lousy programmers inconveniently located next to the boilers and no
thermostats. I'd like to be able to control when each of the boilers can
come on as well as have thermostats in each part of the house to
regulate the temperature in those two zones.
I *think* what I need is a 2 zone programmer like this:
http://www.honeywelluk.com/products/Time-Controls/Wired/ST9500C/
Does that sound plausible? The wiring diagrams don't make it clear that
this will control two boilers; they're using different motorized valves
for the two zones.
Jon
Dave Liquorice
May 23, 2013, 4:23:30 AM5/23/13
to
On Thu, 23 May 2013 08:27:14 +0100, Jon Connell wrote:
> My new house has two boilers heating different parts of the house, but
> lousy programmers inconveniently located next to the boilers and no
> thermostats. I'd like to be able to control when each of the boilers
> can come on as well as have thermostats in each part of the house to
> regulate the temperature in those two zones.
As two independant systems or are the boilers connected on the wet side
> My new house has two boilers heating different parts of the house, but
> lousy programmers inconveniently located next to the boilers and no
> thermostats. I'd like to be able to control when each of the boilers
> can come on as well as have thermostats in each part of the house to
> regulate the temperature in those two zones.
as well?
> I *think* what I need is a 2 zone programmer like this:
the temperature *and* time control then moves to them. So you don't
really require an on/off programmer as well but one can be useful to
force the system off. Programmable stats have "holiday" modes but they
can be a bit awkward to set up compared to adjusting a programmer to OFF.
> Does that sound plausible? The wiring diagrams don't make it clear that
> this will control two boilers; they're using different motorized valves
> for the two zones.
each one as as normal:
Mains -> Programmer -> Thermostat -> Valve. Valve switch -> Boiler.
--
Cheers
Dave.
Jon Connell
May 23, 2013, 4:45:09 AM5/23/13
to
On 23/05/2013 09:23, Dave Liquorice wrote:
> As two independant systems or are the boilers connected on the wet side
> as well?
They're completely independent with no water connections.
> As two independant systems or are the boilers connected on the wet side
> as well?
> More or less but as you are putting in thermostats get programmable ones,
> the temperature *and* time control then moves to them. So you don't
> really require an on/off programmer as well but one can be useful to
> force the system off. Programmable stats have "holiday" modes but they
> can be a bit awkward to set up compared to adjusting a programmer to OFF.
timing from two locations, though thinking about it, the whole idea is
to make the system more automatic rather than the current poor level of
control.
Pity that the Nest doesn't work in the UK yet. They've hinted that they
will bring it to the UK, but nothing concrete that I have seen yet.
> Assuming the two boilers really are independant of each other you wire
> each one as as normal:
>
> Mains -> Programmer -> Thermostat -> Valve. Valve switch -> Boiler.
Jon
Jon Connell
May 23, 2013, 4:53:57 AM5/23/13
to
On Thursday, 23 May 2013 08:27:14 UTC+1, Jon Connell wrote:
> I *think* what I need is a 2 zone programmer like this:
>
> http://www.honeywelluk.com/products/Time-Controls/Wired/ST9500C/
In parallel, I emailed Honeywell to ask if they had a wiring diagram for a 2 boiler system and they emailed me one back within 15 minutes. That qualifies as great support to me.
> I *think* what I need is a 2 zone programmer like this:
>
> http://www.honeywelluk.com/products/Time-Controls/Wired/ST9500C/
Jon
fred
May 23, 2013, 5:16:32 AM5/23/13
to
In article <0ff21bee-99db-45b1...@googlegroups.com>, Jon
Connell <ciam...@gmail.com> writes
The neg on using a controller is that you only get simple on-off timed
control whereas if you use a pair of programmable stats you get to run
the system at a setback temperature of your choice during those 'off'
periods. This is very handy for old thick walled piles in winter (and
summer).
Honeywell stats are very easy to use and set up, and have very simple
day copying options to let you make changes very quickly. Some hard
wired ones can be used with remote sensors too so you can have the
controls together by the boiler or elsewhere away from fiddling fingers
with the temperature sensors in the main rooms if you wish. One neg
however is that Honeywells only run on proportional control, insisting
on cycling the controls multiple times per hour (min 3, default 6 per
hour) which wears out the motorised valves and in my view cycles the
boiler unnecessarily. On a very large house you could find that a remote
rad on low flow is only starting to warm up when the stat thinks it is
time to cycle off again, result, you're paying to heat pipes not rads.
--
fred
it's a ba-na-na . . . .
Connell <ciam...@gmail.com> writes
control whereas if you use a pair of programmable stats you get to run
the system at a setback temperature of your choice during those 'off'
periods. This is very handy for old thick walled piles in winter (and
summer).
Honeywell stats are very easy to use and set up, and have very simple
day copying options to let you make changes very quickly. Some hard
wired ones can be used with remote sensors too so you can have the
controls together by the boiler or elsewhere away from fiddling fingers
with the temperature sensors in the main rooms if you wish. One neg
however is that Honeywells only run on proportional control, insisting
on cycling the controls multiple times per hour (min 3, default 6 per
hour) which wears out the motorised valves and in my view cycles the
boiler unnecessarily. On a very large house you could find that a remote
rad on low flow is only starting to warm up when the stat thinks it is
time to cycle off again, result, you're paying to heat pipes not rads.
--
fred
it's a ba-na-na . . . .
Jon Connell
May 23, 2013, 5:34:50 AM5/23/13
to
On 23/05/2013 10:16, fred wrote:
> The neg on using a controller is that you only get simple on-off timed
> control whereas if you use a pair of programmable stats you get to run
> the system at a setback temperature of your choice during those 'off'
> periods. This is very handy for old thick walled piles in winter (and
> summer).
Old thick walls. Yeah, got them.
> The neg on using a controller is that you only get simple on-off timed
> control whereas if you use a pair of programmable stats you get to run
> the system at a setback temperature of your choice during those 'off'
> periods. This is very handy for old thick walled piles in winter (and
> summer).
dennis@home
May 23, 2013, 5:39:07 AM5/23/13
to
have built in programmers.
You may want a programmer to time the hot water but you can probably use
the existing one.
John Rumm
May 23, 2013, 1:42:22 PM5/23/13
to
On 23/05/2013 08:27, Jon Connell wrote:
appropriate place in the respective zone?
You could basically set the programmers to "always on" then, and let the
programmable stats deal with the timing and variation of temperature.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Jon Connell
May 24, 2013, 3:23:45 AM5/24/13
to
On 23/05/2013 18:42, John Rumm wrote:
> Have you considered simply fitting a prog stat for each boiler in an
> appropriate place in the respective zone?
>
> You could basically set the programmers to "always on" then, and let the
> programmable stats deal with the timing and variation of temperature.
I was hoping for a single point of control to keep things simple, but
> Have you considered simply fitting a prog stat for each boiler in an
> appropriate place in the respective zone?
>
> You could basically set the programmers to "always on" then, and let the
> programmable stats deal with the timing and variation of temperature.
this does appear to be the consensus.
I'm going to play wait-and-see over the summer to see if Nest complete
their trial in the UK and launch a UK-compatible product before the
winter. If not, I have a programmable stat that I failed to get round to
installing in the previous house that I can bring into service for the
zone that currently has the most woeful control (a bust on/off controller).
Jon
Dave Liquorice
May 24, 2013, 5:40:23 AM5/24/13
to
On Thu, 23 May 2013 09:45:09 +0100, Jon Connell wrote:
> I suppose there's the minor inconvenience of having to control the
> timing from two locations, ...
> I suppose there's the minor inconvenience of having to control the
Once you have programable stat and set it up you don't need to keep
tweaking the set point or times as it does that for you, unless one has a
very irregular schedule. Ours only gets tweaked when it gets cold during
the day and we are in that part of the house anyway.
> Pity that the Nest doesn't work in the UK yet.
--
Cheers
Dave.
Dave Liquorice
May 24, 2013, 5:42:31 AM5/24/13
to
On Thu, 23 May 2013 10:39:07 +0100, dennis@home wrote:
> You may want a programmer to time the hot water but you can probably
> use the existing one.
Yes, you don't need one that says "Hot Water" it's just a switch, the
> You may want a programmer to time the hot water but you can probably
> use the existing one.
electrons don't care. Just re-label it, I've reused a HW/CH controller
here for the two heating zones.
--
Cheers
Dave.
John Rumm
May 24, 2013, 9:39:45 AM5/24/13
to
On 24/05/2013 08:23, Jon Connell wrote:
> On 23/05/2013 18:42, John Rumm wrote:
>> Have you considered simply fitting a prog stat for each boiler in an
>> appropriate place in the respective zone?
>>
>> You could basically set the programmers to "always on" then, and let the
>> programmable stats deal with the timing and variation of temperature.
>
> I was hoping for a single point of control to keep things simple, but
> this does appear to be the consensus.
The difficulty you will have is that you need one stat per zone, and
> On 23/05/2013 18:42, John Rumm wrote:
>> Have you considered simply fitting a prog stat for each boiler in an
>> appropriate place in the respective zone?
>>
>> You could basically set the programmers to "always on" then, and let the
>> programmable stats deal with the timing and variation of temperature.
>
> I was hoping for a single point of control to keep things simple, but
> this does appear to be the consensus.
they need to be located somewhere in the zone to be effective. Since
most stats require local adjustment, you arrive at two prog stats as a
simple solution.
There are some controls that will allow you to program both stats from
one location. Vaillant control centres can act as a prog stat and also
control a slave one for a second zone. However they are quite boiler
specific, and they assume that both zones are being driven from the same
boiler.
fred
May 24, 2013, 10:07:04 AM5/24/13
to
In article <7uSdnce1Ls048ALM...@brightview.co.uk>, John
Rumm <see.my.s...@nowhere.null> writes
thermistor IIRC but you need to buy the Honeywell one to get the custom
terminal block that fits in the main unit to connect to the auxiliary
pushfit pins (although I was tight and didn't). I ran the sensor pair
over Cat5e twisted pair that was spare and I have the stat by the boiler
in the kitchen, away from impulsive fingers in the lounge. There's
programmable offset too in case the wiring upsets the set point.
I wouldn't expect wireless to work through too many thick walls but I
have run the CM927 (wireless) through 3 or so thinner solid walls.
I've also modded some non remote sense stats by simply clipping out the
thermistor and remoting it over twisted pair. An easy mod and working
well on my current install after the Honeywell croaked.
>There are some controls that will allow you to program both stats from
>one location. Vaillant control centres can act as a prog stat and also
>control a slave one for a second zone. However they are quite boiler
>specific, and they assume that both zones are being driven from the same
>boiler.
>
Useful info ta.
Rumm <see.my.s...@nowhere.null> writes
>On 24/05/2013 08:23, Jon Connell wrote:
>> On 23/05/2013 18:42, John Rumm wrote:
>>> Have you considered simply fitting a prog stat for each boiler in an
>>> appropriate place in the respective zone?
>>>
>>> You could basically set the programmers to "always on" then, and let the
>>> programmable stats deal with the timing and variation of temperature.
>>
>> I was hoping for a single point of control to keep things simple, but
>> this does appear to be the consensus.
>
>The difficulty you will have is that you need one stat per zone, and
>they need to be located somewhere in the zone to be effective. Since
>most stats require local adjustment, you arrive at two prog stats as a
>simple solution.
>
The Honeywell CM907 wired stat has a remote sensor option, just a 10k
>> On 23/05/2013 18:42, John Rumm wrote:
>>> Have you considered simply fitting a prog stat for each boiler in an
>>> appropriate place in the respective zone?
>>>
>>> You could basically set the programmers to "always on" then, and let the
>>> programmable stats deal with the timing and variation of temperature.
>>
>> I was hoping for a single point of control to keep things simple, but
>> this does appear to be the consensus.
>
>The difficulty you will have is that you need one stat per zone, and
>they need to be located somewhere in the zone to be effective. Since
>most stats require local adjustment, you arrive at two prog stats as a
>simple solution.
>
thermistor IIRC but you need to buy the Honeywell one to get the custom
terminal block that fits in the main unit to connect to the auxiliary
pushfit pins (although I was tight and didn't). I ran the sensor pair
over Cat5e twisted pair that was spare and I have the stat by the boiler
in the kitchen, away from impulsive fingers in the lounge. There's
programmable offset too in case the wiring upsets the set point.
I wouldn't expect wireless to work through too many thick walls but I
have run the CM927 (wireless) through 3 or so thinner solid walls.
I've also modded some non remote sense stats by simply clipping out the
thermistor and remoting it over twisted pair. An easy mod and working
well on my current install after the Honeywell croaked.
>There are some controls that will allow you to program both stats from
>one location. Vaillant control centres can act as a prog stat and also
>control a slave one for a second zone. However they are quite boiler
>specific, and they assume that both zones are being driven from the same
>boiler.
>
Stephen H
May 24, 2013, 5:32:06 PM5/24/13
to
On 24/05/2013 14:39, John Rumm wrote:
> On 24/05/2013 08:23, Jon Connell wrote:
>> On 23/05/2013 18:42, John Rumm wrote:
>>> Have you considered simply fitting a prog stat for each boiler in an
>>> appropriate place in the respective zone?
>>>
>>> You could basically set the programmers to "always on" then, and let the
>>> programmable stats deal with the timing and variation of temperature.
>>
>> I was hoping for a single point of control to keep things simple, but
>> this does appear to be the consensus.
>
> The difficulty you will have is that you need one stat per zone, and
> they need to be located somewhere in the zone to be effective. Since
> most stats require local adjustment, you arrive at two prog stats as a
> simple solution.
>
> There are some controls that will allow you to program both stats from
> one location. Vaillant control centres can act as a prog stat and also
> control a slave one for a second zone. However they are quite boiler
> specific, and they assume that both zones are being driven from the same
> boiler.
>
>
>
>
I have two heating zones myself on two different Prog stats.
> On 24/05/2013 08:23, Jon Connell wrote:
>> On 23/05/2013 18:42, John Rumm wrote:
>>> Have you considered simply fitting a prog stat for each boiler in an
>>> appropriate place in the respective zone?
>>>
>>> You could basically set the programmers to "always on" then, and let the
>>> programmable stats deal with the timing and variation of temperature.
>>
>> I was hoping for a single point of control to keep things simple, but
>> this does appear to be the consensus.
>
> The difficulty you will have is that you need one stat per zone, and
> they need to be located somewhere in the zone to be effective. Since
> most stats require local adjustment, you arrive at two prog stats as a
> simple solution.
>
> There are some controls that will allow you to program both stats from
> one location. Vaillant control centres can act as a prog stat and also
> control a slave one for a second zone. However they are quite boiler
> specific, and they assume that both zones are being driven from the same
> boiler.
>
>
>
>
While I appreciate the issues in having two timeclocks to set date and
time of, I overcame this by ensuring the stats got their date and time
from either Rugby/Anthorn or from Mannheim.... I do not need to set the
date and time on either of them.
I used Salus ST620's one on each floor.
Jon Connell
May 29, 2013, 3:06:12 AM5/29/13
to
On 24/05/2013 22:32, Stephen H wrote:
> I used Salus ST620's one on each floor.
Cheers
> I used Salus ST620's one on each floor.
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