NEST dual zones

[1animal1]

Hi all, Quick query.

I am still renovating my property and still a couple of years away from installing a dual zoned unvented cylinder with system boiler(my plumber doing the necessary work on the boiler/cylinder).

Currently i have a Y plan set up - so if i was to buy a NEST system now, i would simply replace the thermostat and controller with the heat link and NEST thermostat - and NEST will work with the 2 way valve to either direct water to the cylinder or rads. Any holes in this?

Forward thinking - I would prefer my new system to work as an S plan system. So does my theory work?
I would have the boiler running to the pump, then a manifold with 3 pipes, each with their own valve mounted after the mani - 1x zone1, 1x zone2 and the final one going to the hot water tank. The downstairs NEST would then be wired to the Zone 1 and hot water, the upstairs to zone 2 - i can then bring them together on the app to control all three elements. Or would i need to consider a hybrid - Y plan for downstairs (2 way valve to hot water and Z1) and S plan for upstairs (single valve to Z2) from a 2 way manifold mounted after the pump. My guess, being anovice would be the full S system would be more agile.

Thoughts please

 

[Gasmk1]

i dont think it will work as only 2 zones on the nest but you could install a viessmann 4 pipe boiler and unvented cylinder and connect the nest to the 2 heating zones the viessmann has its own internal diverter valve for the hot water.

 

[1animal1]

This was on the assumption of having 2 NEST devices, sorry I wasn't clear on that. So the first NEST would cover Z1 and Hot water valves, and second NEST Z2 in isolation....

Pretty certain you can link both together on the app....

 

[Gasmk1]

https://nest.com/uk/support/article...le-Nest-Learning-Thermostats-in-the-same-home

 

[1animal1]

Thanks - thats the bit i was almost entirely certain about.

What do you think about the theory on a full S plan set up versus a hybrid S/Y plan - from a tradesman, what are the benefits and issues

 

[lewisgriffy]

Hi 1animal1,

I too am renovating (a Victorian house which is 2 1/2 hours away) and have already been at it 3 years! I was 'lucky' in that the house had never had central heating so was able to specify an S+ plan system comprising system gas boiler (Worcester Greenstar but not sure which model)/ ~300L unvented cylinder (unsure which brand) and three CH zones and 1 DHW zone (S+ system).

With regard to hybrid vs. S plan, I personally chose the S+ system due to the size of the house, expansion possibilities, my desire to control CH and DHW from afar, and the nature of the project in that I knew my awareness of the heating requirements would evolve as we peeled back the layers of the neglected house. Had I faced your decision, and knowing how the pipework is laid out adjacent to my boiler, I reckon I'd probably still choose to convert to an S plan setup.

My heating engineer installed the boiler, pipework and gas supply and HW cylinder last year, but since I haven't yet installed any thermostats or radiators (there will be ~20 eventually, incl. 6 towel rails), he hasn't been able to commission it yet. In the meantime, my DHW needs (which are occasional and unsubstantial) are served by an immersion heater which I have to remember to switch off! 4 hrs of immersion heating gives me at least three days' worth of scalding water - it's great. Currently, heating-wise, there's an oil-fired Rayburn and a gas-effect coal fire for the entire house!

I hope the following information doesn't digress from your question and goes some way towards helping with your decisions.

The pipework nearest my boiler so far includes 3 CH flow/return pairs of 22mm for two CH zones (1 pair for ground floor, 1 pair for upper two floors) and the third pair will feed a combined CH/UFH (UFH is <15m2) circuit for a third zone in the future. Another pair of 22mm from the boiler feeds the indirect heating coil in the HW cylinder.

So at the moment, there are 4 control valves (3 of which (2 x CH, 1 x DHW) will be controlled via two Heatlink/Nest units in the first place, and the remaining valve will be controlled by a further Nest/Heatlink when that part of the house is renovated. I plan/hope to add two further zone valves for two further UFH circuits - one for the hallway and one for an adjacent outhouse conversion. These two UFH zones will eventually be controlled by a further two Heatlinks/ Nest thermostats, so I envisage the final setup will have five Heatlinks/thermostats controlling six zone valves.

In your original post you mention the possible use of a manifold system. Although that's not exactly what I've got, it amounts to the same thing, namely from the CH flow/return boiler connections, three flow, and three return branches (via equal tees) extend and feed the three CH zones. My boiler has an integral pump.

I've decided on Nest as although 5 x 3rd gen thermostats/Heatlinks will cost the best part of £1000, Honeywell's Evohome will cost at least twice that (and I can't justify the individual room control to myself or SWMBO), I'm wary of tying myself to BG's Hive, and no-one seems to be raving about Worcester's Wave. I haven't really looked into any others in detail (e.g.Tado). The NestWeave wireless system used by Nest may also be able to integrate into the home automation systems of the future (particularly as Nest is owned by Google - albeit with reservations about its 'big brother' connotations).

So settling on a Heatlink/Nest thermostat setup, as far as I understand it from Nest's website:
1) up to 20/Nest thermostats/Heatlinks can be controlled via the app for one property.
2) one Nest account will allow you to control two properties (i.e. each property could have up up to 20 thermostats/Heatlinks).
3) in my situation I'll use the ground floor Nest thermostat to control 6 radiators and the DHW, via two 2-port zone valves. (I don't suppose there's any need to control DHW from more than one thermostat, unless for disability reasons?)
4) first floor thermostat used to control 6 radiators and 5 towel rails on first and second floors via one 2-port zone valve.

It may help you decide one way or the other, but I could send you photos of my pipework setup/ anticipated wiring connections (for my own understanding - a professional engineer will do the actual connections).

If you'll indulge me, (hopefully on the grounds I'm helping the OP with his decision-making!)rather than beginning a new thread, can I ask: apart from controlling DHW and CH, the 3rd gen Nest thermostat allows compatibility with Open Therm boilers. I know my Worcester boiler isn't Open Therm compatible (and that Open Therm itself is a questionable benefit). So apart from the single 3rd gen thermostat I need to control the DHW, can I save some money by buying 2nd gen thermostats for the other 4 zones, or should I buy 3rd gen all round? I don't currently intend going the 'whole hog' with CO detectors, CCTV etc.

Kind regards,

Ifan

PS - 3rd gen Nest thermostat is £158.99 at Argos today instead of the usual ~£180-£200.

 

[1animal1]

I am just heading out but will reply properly this afternoon Ifan.

Many thanks for the confirmation on your set up and my proposed. It certainly looks like you have your work cut out for you!

I have seen in the instructions for the gen3 NEST that it can work with open themr boilers if this helps - that's on the second the last page where the wiring schematic gives you full instruction - although admittedly I do not know much about that so open to being wrong

Also I have found today that the Amazon Echo works in conjunction with NEST! Fantastic! if a little lazy - progressive steps to full home automation

 

[lewisgriffy]

Thanks 1animal1 - it is a substantial project, and getting the heating setup right will be key!

Unfortunately, Worcester chose to develop their own weather-compensation system than fall in with Open Therm so I won't benefit from that particular feature with my current boiler.

So beyond being able to control DHW and CH with a 3rd gen thermostat, I'm not sure whether I will benefit from the other four being 3rd gen thermostats as well?

If I try to save money through buying 2nd gen instead of 3rd gen stats for the other four zones, will I be sacrificing the Auto Aware capability or are the 2nd gen stats just as capable? Maybe someone could offer some advice on this or I could start a new thread if that were more appropriate.

Good news about the Amazon Echo.

Thanks.

 

[1animal1]

Funnily enough I was just having a similar conversation with a colleague over the 2nd gen working alongside the 3rd gen. You would hope that this would continue - I will be buying one now and another in a couple of years - then use this one as the upstairs zone, with the Auto Aware..and take any upgrade that happens when i buy the second for Z1 and HWT.

Referring to the set up being key - I gather you mean the radiator balancing when all valves are open? I had thought that it could be difficult to set up in that respect, hence why i thought the hybrid S/Y plan could be a way forward. It's what I have now and i never notice the switchover - and don't think I'm likely to in theory.

Going back to your original post - the Honeywell really does look the part and has a few nice plus's with the digital valves. I came to the same conclusion as you - the total cost would take years to recoop, therefore it really does price itself out. I would imagine the S plan with 2x or more zones would be more efficient from the zone perspective regardless - the Honeywell will still utilise the full system everytime it requests heat (albeit with a few rads turned off) - semantics as to which is better overall. The rest really do not have the funds or scope that NEST has with the parent company.

I'm going to have to read up on this open them....to fully understand.

The manifold - I guess buying an actual manifold would be overkill for 3 valves to run off. The valves will fit nicely under the boiler so imagine a single 22mm with T's and a 90 at the bottom will suffice.

You are welcome to keep your question on this post - or set up another in lieu of a lack of replies

Just seen that deal - thanks Ties in nicely having just fitted a nice new remote enabled alarm system which will handle my CCTV. We'll be cooking via apps soon (did you know you can actually buy remote enabled ovens)

Tim

 

[lewisgriffy]

I hadn't thought as far ahead as balancing the radiators, although it will be important I'm sure. I hope I can be as be as certain as I can be that whatever heating system I have is as good as it can be for the old house.

I similarly look at the outlay for the CH controls as being spread over a number of years - that makes it more palatable. However, I don't think I'll be forking out for the Nest CO detectors. Out of interest, which alarm/CCTV system do you have, and was there much cabling/ wiring involved?

Thanks as well for indulging my question.

 

[1animal1]

That's it then, you've convinced me S is the way forward I imagine balancing with all valves open will be the way to do it, as with any closed valves it'll increase the pressure on the rest....

I agree with you on the smoke alarms. They are extortionate and not that subtle... I'm going to go wired and link to the alarm.

Alarm wise I was torn between pyronix and Texecom. I've ended up with the latter which is harder to fit as the programming is infinite. Still to connect it up remotely on the app but I'm getting there with the help of a security forum. Can link you to the 12 pages of learning I've been through if that would help.... It's been a challenge! A lot more than i anticipated considering my light electrical background. Wiring was minimal as I already had one cable run in the house to utilise, then add bit more cable for the two new pirs. If you are handy then it's very rewarding, however it's not for the faint hearted. I have a new found respect for alarm installers

I ended up with a 24w panel, 3 wireless pir, 3 wireless door contacts, 2 wired pir, one wired siren and one wireless siren, remote panel and the ip kit to link it all together. Perfectly adequate kit with expansion capability

 

[lewisgriffy]

Overnight, I've decided to go with 2 x 3rd gen Nest stats in the first place as they'll be located where people will be moving around most of the time. I may then get 2nd gen stats for further zones where the Auto-Aware capability would otherwise overlap with the original two (i.e. overkill with no benefit).

The one tip that's lodged in my brain regarding balancing is to start (with all radiator valves open as you say) with the area of the house which is likely to take the longest to warm up (and I understand this is where the thermostat would also be placed traditionally). If other rooms get overly warm while the coldest area takes its time to warm up, then the radiator valves in those rooms, e.g.thermostatic valves if present (not the lockshields) are closed to different extents allowing 30mins to an hour between each change in order to gauge the effect on individual rads.

With this in mind, I've spent a fair amount of time already wondering whether my ground floor Nest stat would be best placed in the draughty hallway (which will always be draughty and lofty with heat rising up the double staircase) with the result the boiler may permanently be trying to satisfy its call for heat. Hopefully/maybe the Nest's boiler modulation feature is able to compenstate for this and efficiently regulate the gas used in this case.

I intend to re-install the intricate Victorian tiles in the hallway and may take the opportunity to lay a hydronic UFH system (its own zone) while am at it. If so it will also have its own Nest stat and in winter may also cause the boiler to be permanently trying to satisfy it. Otherwise the UFH may help the boiler to satisfy the requirements of the other Nest stat (and so my circular train of thought continues...!) I'd already run pipes for two radiators in the hallway before UFH had even dawned on me, so they will obviously have an effect on the stats as well.

One thing I do like about the Nest stats is, although I've run a dedicated cable to the envisaged location on a hallway wall, I could always move the stat to a warmer room and plug it into a socket where it's more likely to be satisfied within a more reasonable period of time. Downside to this is the silly price 0f ~£30 for a stand!

An alarm system has flashed across my mind every now and then, particularly as the property may be unoccupied for much of the time, but I haven't really looked into it very seriously although now is precisely the time for me to run any cabling necessary. Does the alarm system have a dedicated MCB in your consumer unit?

As I said, running some cable (1.5mm2 or a lighter gauge?) wouldn't yet be too inconvenient. Can I ask why/where you opted for the wired PIR rather than wireless? I guess the wireless door contacts run on batteries (LR44/CR2032 type?) as would contacts for windows? Are you able to silence the siren remotely? Did you mention you have provision for CCTV also?

Does the wattage rating of the panel relate to how many sensors are linked/how many might be linked in future?

If you don't mind me piggybacking your research I'd be grateful for the link.

Many thanks.

 

[1animal1]

Apologies for the late reply Ifan - busy weekend ending with a stinking hangover! Apparently the combination of red/white wine, rum and lager helps reduce the level of water in the brain, creating numerous headaches and feelings of lethargy.

Your theory makes sense regards the NEXT gen 2/3 - Depending on when the 4 comes out could be a big decider, obviously depending on when you are buying.

It sounds like you will end up with a pretty complicated set up given the size of your house. Without seeing the layout makes it difficult to comment - however as an amateur it may well be a futile exercise. Is your plumber of the same mind regards all this?

It's annoying that the NEST stats can't work from a lithium battery I think - you just know the price of the stand is probably to claw back what is probably a loss leader in the main NEST device. Same goes for the other ancillaries.

Regards the alarm - I haven't a dedicated MCB - it is relatively low voltage and i can't see any benefit in having it's own switch. I have merely gone for a 3 amp fused spur off the upstairs ring - the panel has it's own battery back up as do both sirens, so if anything is tampered with or the house power is removed. Protection is maintained. One of my worries was power being cut setting things off - but apparently an alarm that activated on power being removed isn't set up properly.

The wireless devices use lithium CR2's which apparently last 2-4 years. there are several different power saving technologies out there so the lifespan is increasing all the time. My wired ones were convenience more than anything - as my remote pad allowed 2 additional channels and the wiring went into the garage from my hall - i was able to easily wire to the kitchen and garage pir's, negating the need for more batteries and following the advice from alarm installers who prefer wired parts - for obvious reasons, removing the additional doubt of hacking - something that was a lot easier on the older wireless systems. I haven't bothered with contacts for the windows as the PIR's cover these - merely door contacts as i couldn't get wires easily to my front porch, back door or patio doors largely due to inaccessible false ceilings - these are a little more bulky but really easy to fit - you don't really notice them if put in with a bit of thought.

The panel you buy normally dictates how many devices you can attach. You can also buy expanders and various other ancillaries - what i like about mine is that the signals from each wireless jumps to the next device before reaching the panel, so an expander isn't needed unless you have a sizable house with thick walls - so no voltage issues in that respect.

Here's my post - you will immediately see how much I've learnt since starting it - it has been a labour of love/pain to which i can just about see the end. Just this weekend I hooked up my CCTV DVR to the network and got this working remotely - this is because i researched a length a few years ago and bought a really good system - if i was doing it now i would buy all IP cameras feeding to a cloud. After this I'll be hitting the Amazon echo and hooking it all up with smart sockets/switches - it never ends but we love it

Pyronix Homecontrol+ vs Visonic Powermax - Page 13 - !!..DIY Installers..!! - Security Installer Community

 

[1animal1]

PS I didn't go with either system in the title in the end - the Powermax was the older wireless tech so it came down to the Texecom 24W Elite, and Pyronix Homecontrol+

 

[lewisgriffy]

Many thanks once again Tim. It's good to be able to follow a train of thought from initial ideas to final decision.

Wonder if my wife would like an alarm system for Christmas?!

 

[1animal1]

haha - if you get one and she's anything like mine - when she asks the cost, go in at 30% of actual cost. THAT is my biggest piece of advice She doesn't get why we now have one and asked just the other day 'Can we move that alarm box down the side of the house, it's ugly!'.... still to understand the term 'deterrent'.

Note: The Texecom siren with light panel looks infinitely better than the Pyronix box.