I've been fiddling with a number of rads in our badly piped-up house over the last few weeks to encourage some unenthusiastic radiators to start heating up. I've not got a thermometer to balance properly, so I'm largely just going through the process of throttling back the locksheild valves on the well behaved radiators until I start to achieve some balance. Largely nil effect so far (though some occasional glimpses of success).

However, it just occurred to me that the largest rad in the house is in fact the wet UFH in our kitchen, and whilst that is nice and toasty and warm it may well be the largest single drain on the supply.

The whole system is very imperfect. From a WB combi, we have effectively two zones - the UFH zone and the radiators. The hot spewing forth from the boiler goes to the rads (presuming there is a call for heat from the thermostat), and if there is also a call for heat from the thermostat for the UFH then that sucks up part of the supply too. When the main thermostat demands no heat, the UFH thermostat has no live power supply, and therefore the UFH cannot call for heat in its own right - the UFH can only operate when the main stat calls for it.

I'm sure this is far from ideal, but the consequence is that we have always set the thermostat for the UFH to demand heating whenever the rads are calling for it (by setting the UFH thermostat at the lowest level possible). We worked on the presumption that we always wanted some heat in the floor, and didn't consider that there might be some impact on the rest of the system.

Is there likely to be an impact? I *think* that the UF zone and the rad zone divert from one "T" of 15mm piping. There is a pump on the UFH, so I presume there is a maximum flow which it can possibly draw away from the rads - assuming the pump in the UFH is less powerful than the pump in the boiler.

"larkim" wrote in message
...

I've been fiddling with a number of rads in our badly piped-up house over
the last few weeks to encourage some unenthusiastic radiators to start
heating up. I've not got a thermometer to balance properly, so I'm largely
just going through the process of throttling back the locksheild valves on
the well behaved radiators until I start to achieve some balance. Largely
nil effect so far (though some occasional glimpses of success).

However, it just occurred to me that the largest rad in the house is in
fact the wet UFH in our kitchen, and whilst that is nice and toasty and
warm it may well be the largest single drain on the supply.

The whole system is very imperfect. From a WB combi, we have effectively
two zones - the UFH zone and the radiators. The hot spewing forth from the
boiler goes to the rads (presuming there is a call for heat from the
thermostat), and if there is also a call for heat from the thermostat for
the UFH then that sucks up part of the supply too. When the main
thermostat demands no heat, the UFH thermostat has no live power supply,
and therefore the UFH cannot call for heat in its own right - the UFH can
only operate when the main stat calls for it.

I'm sure this is far from ideal, but the consequence is that we have always
set the thermostat for the UFH to demand heating whenever the rads are
calling for it (by setting the UFH thermostat at the lowest level
possible). We worked on the presumption that we always wanted some heat in
the floor, and didn't consider that there might be some impact on the rest
of the system.

Is there likely to be an impact? I *think* that the UF zone and the rad
zone divert from one "T" of 15mm piping. There is a pump on the UFH, so I
presume there is a maximum flow which it can possibly draw away from the
rads - assuming the pump in the UFH is less powerful than the pump in the
boiler.

Or am I barking up the wrong tree considering whether the UFH is having any
impact at all on the balancing of the rest of the system?

TIA!

Matt

Does the UFH not have a manifold with a mixing valve and a flow throttling
valve so that you can reduce its demand ?

AWEM

On Friday, 15 February 2013 12:53:40 UTC, Andrew Mawson wrote:
"larkim" wrote in message

...



I've been fiddling with a number of rads in our badly piped-up house over

the last few weeks to encourage some unenthusiastic radiators to start

heating up. I've not got a thermometer to balance properly, so I'm largely

just going through the process of throttling back the locksheild valves on

the well behaved radiators until I start to achieve some balance. Largely

nil effect so far (though some occasional glimpses of success).



However, it just occurred to me that the largest rad in the house is in

fact the wet UFH in our kitchen, and whilst that is nice and toasty and

warm it may well be the largest single drain on the supply.



The whole system is very imperfect. From a WB combi, we have effectively

two zones - the UFH zone and the radiators. The hot spewing forth from the

boiler goes to the rads (presuming there is a call for heat from the

thermostat), and if there is also a call for heat from the thermostat for

the UFH then that sucks up part of the supply too. When the main

thermostat demands no heat, the UFH thermostat has no live power supply,

and therefore the UFH cannot call for heat in its own right - the UFH can

only operate when the main stat calls for it.



I'm sure this is far from ideal, but the consequence is that we have always

set the thermostat for the UFH to demand heating whenever the rads are

calling for it (by setting the UFH thermostat at the lowest level

possible). We worked on the presumption that we always wanted some heat in

the floor, and didn't consider that there might be some impact on the rest

of the system.



Is there likely to be an impact? I *think* that the UF zone and the rad

zone divert from one "T" of 15mm piping. There is a pump on the UFH, so I

presume there is a maximum flow which it can possibly draw away from the

rads - assuming the pump in the UFH is less powerful than the pump in the

boiler.



Or am I barking up the wrong tree considering whether the UFH is having any

impact at all on the balancing of the rest of the system?



TIA!



Matt



Does the UFH not have a manifold with a mixing valve and a flow throttling

valve so that you can reduce its demand ?



AWEM

I presume it does, yes, so perhaps that might be an area to fiddle with to get the temps up.

Matt

On Feb 15, 12:09*pm, larkim wrote:
I've been fiddling with a number of rads in our badly piped-up house over the last few weeks to encourage some unenthusiastic radiators to start heating up. *I've not got a thermometer to balance properly, so I'm largely just going through the process of throttling back the locksheild valves on the well behaved radiators until I start to achieve some balance. *Largely nil effect so far (though some occasional glimpses of success).

However, it just occurred to me that the largest rad in the house is in fact the wet UFH in our kitchen, and whilst that is nice and toasty and warm it may well be the largest single drain on the supply.

The whole system is very imperfect. From a WB combi, we have effectively two zones - the UFH zone and the radiators. *The hot spewing forth from the boiler goes to the rads (presuming there is a call for heat from the thermostat), and if there is also a call for heat from the thermostat for the UFH then that sucks up part of the supply too. *When the main thermostat demands no heat, the UFH thermostat has no live power supply, and therefore the UFH cannot call for heat in its own right - the UFH can only operate when the main stat calls for it.

I'm sure this is far from ideal, but the consequence is that we have always set the thermostat for the UFH to demand heating whenever the rads are calling for it (by setting the UFH thermostat at the lowest level possible). *We worked on the presumption that we always wanted some heat in the floor, and didn't consider that there might be some impact on the rest of the system.

Is there likely to be an impact? *I *think* that the UF zone and the rad zone divert from one "T" of 15mm piping. *There is a pump on the UFH, so I presume there is a maximum flow which it can possibly draw away from the rads - assuming the pump in the UFH is less powerful than the pump in the boiler.

Or am I barking up the wrong tree considering whether the UFH is having any impact at all on the balancing of the rest of the system?

TIA!

Matt

The pipework resistance in most UFH systems is much higher than
radiators making balancing virtually impossible.
This is why the UFH usually has it's own separate pump and manifold
and can be considered a separate system.
If you haven't got this, this may be your problem

http://www.discountedheating.co.uk/s...n&currency=GBP

On Friday, 15 February 2013 19:34:00 UTC, Roger Mills wrote:
On 15/02/2013 12:09, larkim wrote:

I've been fiddling with a number of rads in our badly piped-up house over the last few weeks to encourage some unenthusiastic radiators to start heating up. I've not got a thermometer to balance properly, so I'm largely just going through the process of throttling back the locksheild valves on the well behaved radiators until I start to achieve some balance. Largely nil effect so far (though some occasional glimpses of success).



However, it just occurred to me that the largest rad in the house is in fact the wet UFH in our kitchen, and whilst that is nice and toasty and warm it may well be the largest single drain on the supply.



The whole system is very imperfect. From a WB combi, we have effectively two zones - the UFH zone and the radiators. The hot spewing forth from the boiler goes to the rads (presuming there is a call for heat from the thermostat), and if there is also a call for heat from the thermostat for the UFH then that sucks up part of the supply too. When the main thermostat demands no heat, the UFH thermostat has no live power supply, and therefore the UFH cannot call for heat in its own right - the UFH can only operate when the main stat calls for it.



I'm sure this is far from ideal, but the consequence is that we have always set the thermostat for the UFH to demand heating whenever the rads are calling for it (by setting the UFH thermostat at the lowest level possible). We worked on the presumption that we always wanted some heat in the floor, and didn't consider that there might be some impact on the rest of the system.



Is there likely to be an impact? I *think* that the UF zone and the rad zone divert from one "T" of 15mm piping. There is a pump on the UFH, so I presume there is a maximum flow which it can possibly draw away from the rads - assuming the pump in the UFH is less powerful than the pump in the boiler.



Or am I barking up the wrong tree considering whether the UFH is having any impact at all on the balancing of the rest of the system?



TIA!



Matt



It ain't going to work very well if the UFH can't be on without the

radiators because the UFH has a lot more thermal inertia and needs to

come much earlier in the morning.



It would be usual to have the equivalent of an S-Plan system with the

UFH and radiators in separate zones - each with a zone valve controlled

by a thermostat, and wired so that the boiler only runs when either one

or both zones are calling for heat.



Because the water circulating through the UFH needs to be at a much

lower temperature than that going through the rads (typically 40 degrees

rather than 70 or 80) there should be a mixing valve which controls the

temperature by mixing return water with newly heated water. There should

be a dedicated pump which circulates water just round the UFH circuit,

whilst the main pump runs the radiators and delivers newly heated water

to the UFH circuit (but not round it).



I think that you need to make a close examination of what you've

actually got, and then work out what needs to be done to make it work

properly. Inserting a couple of zone valves and a bit of wiring

shouldn't be too difficult, and might make a dramatic difference.



If there's a lot of contention between zones, you could arrange the

timing so that they're not often on at the same time.

--

Cheers,

Roger

____________

Please reply to Newsgroup. Whilst email address is valid, it is seldom

checked.

Cheers. Yes, there is a separate manifold and pump for the UFH system. And for practical purposes, the UFH does in fact work well, even though it can't call for heat without the rest of the system demanding heat too, though I agree it is slightly peculiar that it can't operate of its own devices.

I know that it isn't "right", but (as far as the UFH goes) it works. And now that others have posted that there is unlikely to be a conflict between the UFH and the radiators in terms of balancing pressures, I think we'll leave well alone!

Thanks for taking the time to respond!

Matt

On 18/02/2013 11:11, larkim wrote:

Cheers. Yes, there is a separate manifold and pump for the UFH system. And for practical purposes, the UFH does in fact work well, even though it can't call for heat without the rest of the system demanding heat too, though I agree it is slightly peculiar that it can't operate of its own devices.

I know that it isn't "right", but (as far as the UFH goes) it works. And now that others have posted that there is unlikely to be a conflict between the UFH and the radiators in terms of balancing pressures, I think we'll leave well alone!

Thanks for taking the time to respond!

So the UFH has it's own manifold and pump. That would be a very simple
job to add a single zone valve into the CH feed to the UFH manifold.

Re-direct the power that currently runs the UFH manifold pump through a
room 'stat in the kitchen then into a new zone valve in the boiler
feed/flow that goes to the UFH Manifold and have the switched power from
the zone valve feed the UFH pump.
If as you say the UFH works very well and is "toasty" then it could be
far more efficient if it's reigned in when kitchen is up to temp
allowing the radiator circuit to work by it's self.

Pete@
--
http://www.GymRatZ.co.uk
Commercial Gym Equipment and Home Fitness stuff since 1999.