Our re-furb is grinding ever onwards approaching completion asymptotically
(i.e. never getting there!).

We have wet under floor heating in one part, and conventional radiators
elsewhere, both heated by a Grant oil fired boiler. Should we have a three
zone controller, for a/ Hot water, b/ Radiators and c/ the three under floor
areas (which each have a thermostat. or should the under floor and the
radiators be on the same output from the controller?

AWEM

On 17/12/12 19:49, Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional radiators
elsewhere, both heated by a Grant oil fired boiler. Should we have a
three zone controller, for a/ Hot water, b/ Radiators and c/ the three
under floor areas (which each have a thermostat. or should the under
floor and the radiators be on the same output from the controller?

AWEM
3 way controller. the response times of an in screed system is RADICALLY
different from the radiator system.

If you want to go two way couple the hot water to e.g the UFH system
timer wise.

Fit three master stats anyway and run as three zones. As well as
zone/radiator stats.

The tank stat can be the sole HW stat





--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

Andrew Mawson wrote:


We have wet under floor heating in one part, and conventional radiators
elsewhere, both heated by a Grant oil fired boiler. Should we have a three
zone controller, for a/ Hot water, b/ Radiators and c/ the three under floor
areas (which each have a thermostat. or should the under floor and the
radiators be on the same output from the controller?

I'd have them on the same output as the CH, but have a separate stat for
each area.
Gets more complicated with the piping, but fairly straightforward and
common.
You can then set the floor for, say, 15 degrees, and the CH for 20.

--
To reply by e-mail, change the ' + ' to 'plus'.

On 17/12/12 20:06, A.Lee wrote:
Andrew Mawson wrote:


We have wet under floor heating in one part, and conventional radiators
elsewhere, both heated by a Grant oil fired boiler. Should we have a three
zone controller, for a/ Hot water, b/ Radiators and c/ the three under floor
areas (which each have a thermostat. or should the under floor and the
radiators be on the same output from the controller?

I'd have them on the same output as the CH, but have a separate stat for
each area.
Gets more complicated with the piping, but fairly straightforward and
common.
You can then set the floor for, say, 15 degrees, and the CH for 20.

NO. never on the same timer. Screed floors take HOURS to warm fully, and
you may want more intelligence on the thermostat to minimise overshoot.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Dec 17, 7:49*pm, "Andrew Mawson"
wrote:
Our re-furb is grinding ever onwards approaching completion asymptotically
(i.e. never getting there!).

We have wet under floor heating in one part, and conventional radiators
elsewhere, both heated by a Grant oil fired boiler. Should we have a three
zone controller, for a/ Hot water, b/ Radiators and c/ the three under floor
areas (which each have a thermostat. or should the under floor and the
radiators be on the same output from the controller?

AWEM

The number of zones in a building depends on the occupation pattern.
Some areas will be constantly occupied, others perhaps infrequently
so.
So these areas can be divided apart and independently controlled.
Also if some areas are significantly warmer than others.

So fuel savings can be made.

This has been done in large commercial buildings for years.
It only becomes viable in domestic houses as fuel prices rise. After
all you can turn radiators off manually.
However even now, you'd need a big house to make it worth while.

The alternative method is for each zone to have it's own heat source/
boiler which in some cases works out cheaper.

With regard to underfloor heating.
This allows boilers to run efficiently because of low water
temperatures.

However, it can't be turned on and off daily as it has high thermal
inertia. Probably going to take a couple of days to warm up from cold.
It needs to be installed in a well insulated building.
Sometimes the UF heating is used as "background heat" and topped up
from other sources as required.

On Dec 18, 8:18*am, harry wrote:
With regard to underfloor heating.
This allows boilers to run efficiently because of low water
temperatures.

Only if the boiler isn't required to feed anything else! As our
boiler feeds radiators and a hot water cylinder in addition to the UFH
it runs at a fairly high flow temperature of 65C. The UFH manifold
arrangement incorporates a thermostatic mixer valve to reduce the
temperature to 45C for that circuit.

Richard.
http://www.rtrussell.co.uk/

On Dec 17, 7:49*pm, "Andrew Mawson"
wrote:
We have wet under floor heating in one part, and conventional radiators
elsewhere

Our situation is the same: UFH downstairs and radiators upstairs (plus
hot water). The radiators and hot water are controlled by a
conventional timeswitch, but not the UFH: as far as the boiler is
concerned that's 'permanently on'.

The UFH zones (we have 6) each have their own UFH thermostats; they
switch between 17C and 21C according to the time of day, but again
they never turn the system 'off'. The UFH can, and does, come on in
the middle of the night in order to maintain the 17C minimum.

Richard.
http://www.rtrussell.co.uk/

On 17/12/2012 19:49, Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional radiators
elsewhere, both heated by a Grant oil fired boiler. Should we have a
three zone controller, for a/ Hot water, b/ Radiators and c/ the three
under floor areas (which each have a thermostat. or should the under
floor and the radiators be on the same output from the controller?

2 way from boiler output HW/CH then split off the CH to a single zone
valve going to radiator zone and straight feed to UFH manifold.
When I did ours (combi. so same really except it's either HW /or/ CH
without the benefit of the centre position of a 2 way zone valve) I put
2 single zone valves to isolate either the C/H or the UFH however, as
someone else mentioned, the UFH circuit is always on (on the timer) with
the 4 individual UFH zones calling for heat or not depending on time of
day and their individual prog. stat. settings so I haven't ever wired up
the zone valve to the UFH manifold.
When all UFH zones are satisfied very little water can bypass the
manifold pump, besides which the bedroom radiators are only on for a few
hours in the morning and most of the evening so the UFH zone is always
drawing heat when it's radiator time making UFH manifold isolation
unnecessary.

Having bedroom radiators as a single zone with individual radiator stat.
valves works just fine and the whole zone can be set to a more realistic
18 degrees on it's own room stat on the landing.

I don't use the UFH manifold to reduce flow temperature as the bedroom
radiators perform admirably even with a MAX. boiler flow of 55 degrees
(this temperature only being pumped when outdoor temp. is -1 or lower)
But the bedrooms are downstairs and partially underground and have never
dropped below 12 degrees through the last 6 years of having no heating
whatsoever.
:¬)

Pete
--
http://www.GymRatZ.co.uk
Home and Commercial Gym Equipment, WaterRowers etc

Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional
radiators elsewhere, both heated by a Grant oil fired boiler. Should
we have a three zone controller, for a/ Hot water, b/ Radiators and
c/ the three under floor areas (which each have a thermostat. or
should the under floor and the radiators be on the same output from
the controller?

Unless you actually want to turn the UFH off via a programmer then there is
no need to have a 3 zone controller. The programmable stats in your 3 UFH
zones should do their job and these should have a permanent live.

--
Adam

On 22/12/12 12:42, ARW wrote:
Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional
radiators elsewhere, both heated by a Grant oil fired boiler. Should
we have a three zone controller, for a/ Hot water, b/ Radiators and
c/ the three under floor areas (which each have a thermostat. or
should the under floor and the radiators be on the same output from
the controller?

Unless you actually want to turn the UFH off via a programmer then there is
no need to have a 3 zone controller. The programmable stats in your 3 UFH
zones should do their job and these should have a permanent live.

That is a reasonably valid point EXCEPT that most UFH zone valves
controlled by stats are NOT master stats as such and do NOT stop the
pump running. Not the UFH pump: not the boiler pump.

They are analagous to TRVs in radiators.

Now you COULD fit motorised valves, at which point the points you make
become valid, because you can wire OR the outputs and use them to
control the pumps. But that is not the way most installations work.

In the end you need a time because you don't want to heat when you don't
need to. That might be in the thermostats or it might not, but its still
needed.


What all this means is that UFH needs to be thought through carefully
and 'conventional thinking' does not apply.



--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

Take care with what UFH system you have ... many have a temp that is
much less than rads and if you run them at rad temp they will fail.

That is why many are used with Thermal store with 2 heat exchangers ....
1 for DHW the other at bottom of store for UFH supply

On 22/12/2012 12:42, ARW wrote:
Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional
radiators elsewhere, both heated by a Grant oil fired boiler. Should
we have a three zone controller, for a/ Hot water, b/ Radiators and
c/ the three under floor areas (which each have a thermostat. or
should the under floor and the radiators be on the same output from
the controller?

Unless you actually want to turn the UFH off via a programmer then there is
no need to have a 3 zone controller. The programmable stats in your 3 UFH
zones should do their job and these should have a permanent live.

"Rick Hughes" wrote in message
news

On 22/12/2012 12:42, ARW wrote:
Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional
radiators elsewhere, both heated by a Grant oil fired boiler. Should
we have a three zone controller, for a/ Hot water, b/ Radiators and
c/ the three under floor areas (which each have a thermostat. or
should the under floor and the radiators be on the same output from
the controller?

Unless you actually want to turn the UFH off via a programmer then there
is
no need to have a 3 zone controller. The programmable stats in your 3 UFH
zones should do their job and these should have a permanent live.


Take care with what UFH system you have ... many have a temp that is much
less than rads and if you run them at rad temp they will fail.

That is why many are used with Thermal store with 2 heat exchangers .... 1
for DHW the other at bottom of store for UFH supply

No chance of that as the ufh manifold has a hot/cold mixer to maintain the
lower temp in the floor. (Three zone controller fitted this afternoon
incidentally)

AWEM

Andrew Mawson wrote:
"Rick Hughes" wrote in message
news

On 22/12/2012 12:42, ARW wrote:
Andrew Mawson wrote:
Our re-furb is grinding ever onwards approaching completion
asymptotically (i.e. never getting there!).

We have wet under floor heating in one part, and conventional
radiators elsewhere, both heated by a Grant oil fired boiler.
Should we have a three zone controller, for a/ Hot water, b/
Radiators and c/ the three under floor areas (which each have a
thermostat. or should the under floor and the radiators be on
the same output from the controller?

Unless you actually want to turn the UFH off via a programmer
then there is
no need to have a 3 zone controller. The programmable stats in
your 3 UFH zones should do their job and these should have a
permanent live.

Take care with what UFH system you have ... many have a temp that
is much less than rads and if you run them at rad temp they will
fail. That is why many are used with Thermal store with 2 heat
exchangers
.... 1 for DHW the other at bottom of store for UFH supply

No chance of that as the ufh manifold has a hot/cold mixer to
maintain the lower temp in the floor. (Three zone controller fitted
this afternoon incidentally)

That is what happens on the ones I have wired up.
--
Adam