Adding UFH to new conservatory-tee off boiler before pump?

[iwest]

Hi there, a question for you... I have a 1972 house with an open vented heating system as follows:
In loft: cold water tank and heating vent cold water tank
Upstairs landing airing cupboard: hot water cylinder, pump, 3 way motorised valve (Y plan), drayton wiring centre
Upstairs landing: Honeywell controller/programmer for water/heat
Downstairs: roomstat
Downstairs utlilty room: 17 year old oil boiler.

The boiler is broken (rusted water jacket) and I was going to get it replaced with a Worcester Greenstar Utility 18/25 oil condensing boiler.

The point of the post is: at the same time I am building a conservatory right beside the utility room (i.e v close to the boiler), so the question is: if I was to fit direct boiler control underfloor heating in the conservatory:

1) Can I tee off directly from the boiler flow/return to the UFH (for example the nu heat onezone kit). I ask this because all the schematics on t'internet from various suppliers show the boiler flow pipe, then the pump, then the tee off to the UFH. Obviously with the pump upstairs I would prefer to tee off by the boiler.

2) My current boiler or the replcament Utility 18/25 does not (as far as I know) have pump overrun, if it did does this change anything.

Many thanks!

 

[muggles]

Building regs do not permit you to extend your heating system into a conservatory unless the conservatory is building regs compliant, which most aren't. You need to put in a completely separate heat source.

 

[big-all]

a conservatory will not heat up with underfloor heating unless its a warmish day
you need up to 6kw off heating to warm a conservatory on a very cold day

 

[DeltaT2]

Hi there, a question for you... I have a 1972 house with an open vented heating system as follows:
In loft: cold water tank and heating vent cold water tank
Upstairs landing airing cupboard: hot water cylinder, pump, 3 way motorised valve (Y plan), drayton wiring centre
Upstairs landing: Honeywell controller/programmer for water/heat
Downstairs: roomstat
Downstairs utlilty room: 17 year old oil boiler.

The boiler is broken (rusted water jacket) and I was going to get it replaced with a Worcester Greenstar Utility 18/25 oil condensing boiler.

The point of the post is: at the same time I am building a conservatory right beside the utility room (i.e v close to the boiler), so the question is: if I was to fit direct boiler control underfloor heating in the conservatory:

1) Can I tee off directly from the boiler flow/return to the UFH (for example the nu heat onezone kit). I ask this because all the schematics on t'internet from various suppliers show the boiler flow pipe, then the pump, then the tee off to the UFH. Obviously with the pump upstairs I would prefer to tee off by the boiler.

2) My current boiler or the replcament Utility 18/25 does not (as far as I know) have pump overrun, if it did does this change anything.

Many thanks!

Of course you can heat a new conservatory with UFH, you just ensure that the 'heatloss' is minimum, in fact if you are getting a Building Warrant for this project, you can state it's a Heating Conservatory & ensure all fabric 'U' values are as good as poss. A UFH area can be added to any Central Heating system.............Many, many details of this on-line.

 

[iwest]

Thanks for the replies, I am happy with what I am doing and the UFH will be independent of the house heating, but my questions are simply about where to tee off the boiler relative the pump etc ..... anyone!!

 

[DeltaT2]

The UFH would act as an additional zone on your system, so it needs to be piped in such a way that there will be no heat migration to other zones when it's on. So you would be better fitting 3 x 2 port zone valves, 1 for HW, 1 for Rads & 1 for UFH. If you retain your Mid-poss valve there's a chance you'll be heating hot water while the UFH is on. That should take care of the UFH Flow, for the Return; ensure it's connected to the common Return at the correct place, so you don't get any heat migration through the radiators.
Hope that's some help?

 

[muggles]

Thanks for the replies, I am happy with what I am doing and the UFH will be independent of the house heating, but my questions are simply about where to tee off the boiler relative the pump etc ..... anyone!!

It can't be independent of the house heating, from a BR point of view, if it's teed off the boiler anywhere. In order to comply with the 2010 update to BRs it must be a completely separate, independent heat source, not connected or plumbed into your boiler circuit in any way, even with independent control. You simply can't do it

 

[lucasdodds]

Hi Iwest. Did you ever get a reply? I have the same question. Can you T-off the UFH before the pump? What did you do in the end?

 

[Madrab]

@lucasdodds You may struggle to get a reply from @iwest as the last time he was on was the March 22 but I've tagged his ID for you

 

[Madrab]

Just to add - When it comes to UFH, if it will be controlled by a manifold and it's own pump/blending, then yes it can tee off before the main system pump.

The Building Regs requirements still hold true though. The regs state - Conservatories are normally exempt from building regs when :

• They are built at ground level and are less than 30 square metres in floor area.
• The conservatory is separated from the house by external quality walls, doors or windows.
• There should be an independent heating system with separate temperature and on/off controls.
• Glazing and any fixed electrical installations comply with the applicable building regulations requirements (see below).
• The conservatory is single storey.

That specification means a system cannot tee into a conservatory from the main central heating and still comply. The minute it is connected to the main CH system, it is then considered as an extension and not a conservatory, it then needs to follow the regs.

 

[Notch7]

That specification means a system cannot tee into a conservatory from the main central heating and still comply. The minute it is connected to the main CH system, it is then considered as an extension and not a conservatory, it then needs to follow the regs

You might find this useful, I used to refer to this when Inwas building orangeries for clients:

LABC have issued guidance notes to update this as they realised it made little sense forcing householders to heat a conservatory with a heat source less efficient than the main boiler.

The guidance notes state central heating can be extended into a non compliant room (typically Conservatory / orangery), provided it had separate thermostatic controls ( a TRV is mentioned for rads).

however the glazing should be compliant to u values in table 1.1 of part L1b, although area of glazing doesn’t apply.

https://www.premierroofsystems.co.uk/wp-content/uploads/2014/11/labc_4893_techg_conservatories.pdf

 

[Madrab]

Interesting and if you read through the document, it states it still stays exempt if - when using the existing CH system as long as it has controls (TRV's/Valves/etc), then the next paragraph contradicts that - but when you read the latest L1B (2021, that came into force the middle of 2022) under paragraph 0.6 (new dwelling), 0.14 (e) (exemptions) - If the heating system from the dwelling is extended into the conservatory the exemption status for conservatories is removed and the conservatory is then considered to be an extension therefore is not exempt and then section 10.13 doesn't apply.

That and that document is referencing the old Doc L1B which is now superceded

As usual, the regs re very ambiguous.

 

[lucasdodds]

Hi, I want to install an UFH on ground floor. Boiler is on ground floor but cylinder and pump is on second floor. All connection instructions show the UFH connected after the pump. That woul dean running a pipe drown back to ground floor. Q: Can I T off from the boiler on the ground floor before it reaches the pump upstairs? Can anyone advise? Thanks

 

[Mr Chibs]

Could you not fit a 'room' kit with pump, like a Polypipe ZRU, you just take a 'tee' off the flow and return, then add a zone valve and thermostat so this can be controlled independently. I'm on a combi, but someone will say if it's possible that way with heat/system boiler.

 

[Madrab]

Boiler is on ground floor but cylinder and pump is on second floor

If the UFH doesn't have it's own pump and manifold/blending valve then no, it probably wouldn't feed to the UFH properly unless it's a tiny loop.