Home heating automation

digiman

deezell wrote: »

If money is no object, go for the Evohome. A 12 rad max kit plus the HW relay system with HW temperature sensor and display will do everything you ask for about €1k, installation not included.
If your rads already have manual TRVs, then its a technical install, no plumbing required. If your rads have screw tap like valves, each rad will need one TRV valve body to take a TRV head. A job for the plumber while he installs your attic plumbing.
I count 13 rads, so you may need to leave a selected rad open, which will heat for any TRV activity in its zone. Towel rail might suit, its normal to have one rad open in a full TRV installation so the circuit is never fully closed. Some towel rails may have awkward connections for a TRV valve body, or it may look unsightly on the rail. You will need to latch your existing CH motorised zone valves to permanently open, but the HW zone valve can be retained.
The Eddie will continue to function as normal, though you will now be able to see the Hot water temperature rise associated with diverted solar PV energy from the Eddie.

1. You will need a TRV per rad, otherwise open rads will heat for any room call.
2. See above.

3. Evohome HW control has a temperature sensor.

My existing radiator valves are exactly like the one in this page here:

https://www.screwfix.ie/p/eph-controls-emtrv15-white-angled-trv-lockshield-15mm-x-/134HP?gclid=EAIaIQobChMIv7zzr9We7QIVjMLtCh1-CQMPEAQYKCABEgL0rPD_BwE&gclsrc=aw.ds

Does this go down as a technical install?

So can you see the hot water temp in the app itself? Would be interested to see this trend overtime as the Eddie heats up the water. Is installing that temperature sensor for the hot water tank a technical install as well?

At this stage the Honeywell evohome seems to be about 3 years old. Is there anything else that has come out or due to come out that would be as good but have newer features?

deezell

baldshin wrote: »

Here's how he has it wired up. Certainly differently to your diagram. I've emailed them back and requested a refund and will possibly have a look myself at sorting tomorrow if time allows.

He's just wired it as a fully pumped or S plan 2 zone system. He's probably unaware that your 2 zone system is a gravity system. He's wired CH to fire the boiler, (black wire to 3) and HW to drive the pump (grey wire to 6). You need to remove black from 3. and move the grey from 6 to 3, plus add a link from 3 to 4. Move brown from 5 to 6, and connect black to 5. This will fulfil the wiring on my diagram.
I notice on the image that he has connnected a single wire to the 12v T1 connection. The T1 T2 connectors are there to supply 12v back up the old isolated wire pair to your original mechanical stat location in order to supply 12v to power the Nest without the need of the mains adaptor. I'm not sure why he has only connected one terminal, T1, and used the other wire to connect the earth terminal. If your Nest is installed at the old stat location without the mains adaptor it won't charge, and will run out of power. Unless the T2 terminal is internally grounded to earth, I don't see how it can power the stat on the wall, as the 12v is supplied from the T1 and T2.

deezell

digiman wrote: »

My existing radiator valves are exactly like the one in this page here:

https://www.screwfix.ie/p/eph-controls-emtrv15-white-angled-trv-lockshield-15mm-x-/134HP?gclid=EAIaIQobChMIv7zzr9We7QIVjMLtCh1-CQMPEAQYKCABEgL0rPD_BwE&gclsrc=aw.ds

Does this go down as a technical install?

So can you see the hot water temp in the app itself? Would be interested to see this trend overtime as the Eddie heats up the water. Is installing that temperature sensor for the hot water tank a technical install as well?

At this stage the Honeywell evohome seems to be about 3 years old. Is there anything else that has come out or due to come out that would be as good but have newer features?

I've read post expressing concern at the lack of upgrade of the Evohome, but if it's not broken, etc.. You could achieve the same system with Drayton Wiser or Tado, a goid few quid less, but no measurement of cylinder HW temperature on their apps. A cheap Sonoff device and sensor will give you a Sonoff app to read this. The Evohome sensor just pops onto the cylinder surface (CS92) or into a sensor port (ATF500DHW) on your cylinder.
Your valves are ready for the TRV heads, so no plumbing, just fit the heads as per instructions, the rest is techie stuff, but DIY-able.

digiman

deezell wrote: »

I've read post expressing concern at the lack of upgrade of the Evohome, but if it's not broken, etc.. You could achieve the same system with Drayton Wiser or Tado, a goid few quid less, but no measurement of cylinder HW temperature on their apps. A cheap Sonoff device and sensor will give you a Sonoff app to read this. The Evohome sensor just pops onto the cylinder surface (CS92) or into a sensor port (ATF500DHW) on your cylinder.
Your valves are ready for the TRV heads, so no plumbing, just fit the heads as per instructions, the rest is techie stuff, but DIY-able.

Thanks, will just keep an eye out for deal this week then so

legend99

deezell wrote: »

I've read post expressing concern at the lack of upgrade of the Evohome, but if it's not broken, etc.. You could achieve the same system with Drayton Wiser or Tado, a goid few quid less, but no measurement of cylinder HW temperature on their apps. A cheap Sonoff device and sensor will give you a Sonoff app to read this. The Evohome sensor just pops onto the cylinder surface (CS92) or into a sensor port (ATF500DHW) on your cylinder.
Your valves are ready for the TRV heads, so no plumbing, just fit the heads as per instructions, the rest is techie stuff, but DIY-able.

You're a Tado man right? How come you'd pick Evohome?

deezell

legend99 wrote: »

You're a Tado man right? How come you'd pick Evohome?

I didn't, it's what the man wanted, with HW temperature readout, and he didn't mind the cost, so..
Another reason, if you're going to have 10-12 or thereabouts individual zones, its probably convenient to have a fixed purpose display with multiple zones on screen such as the Evohome terminal, with other systems you only have the wall stats or the app. You could of course plug in a cheap android tablet sitting in a stand and have the Tado web interface always on with loads of zones, but that's a bodge, not a product.
Tado can do HW temperature btw, but only in OT connected system boilers with direct HW.
I rate the Tado highly, but I'm not an agent for them. Evohome has its fans, some of them are total devotees. It's a robust high end system, albeit a little dated. Personally, I think the TRVs are fussy looking. Horses for courses I suppose.

legend99

deezell wrote: »

I didn't, it's what the man wanted, with HW temperature readout, and he didn't mind the cost, so..
Another reason, if you're going to have 10-12 or thereabouts individual zones, its probably convenient to have a fixed purpose display with multiple zones on screen such as the Evohome terminal, with other systems you only have the wall stats or the app. You could of course plug in a cheap android tablet sitting in a stand and have the Tado web interface always on with loads of zones, but that's a bodge, not a product.
Tado can do HW temperature btw, but only in OT connected system boilers with direct HW.
I rate the Tado highly, but I'm not an agent for them. Evohome has its fans, some of them are total devotees. It's a robust high end system, albeit a little dated. Personally, I think the TRVs are fussy looking. Horses for courses I suppose.

Fair points. I find here that as I use Tado on my phone that I'm the only one with knowledge of it. I can see why the Evohome display is good - I wonder would Tado develop one? Although their record at new devices is pretty bad - plus the cost, e.g. the Wireless Thermostat when the request on the community page was for a basic external sensor!

Anyway, I'm going to pop the Sonoff on the cylinder at the weekend. You might have a think about the question I had re switching thermostat to wireless as reading online a good few people suggest keeping it in hall for the very reason of stopping the hall being freezing and passing cold on.

I might actually post up the house layout and wouldn't mind have an over and back with you re ideal set-up as I'm enjoying the thinking it out. I have 11 TRVs (14 rads) but I need to replace the heads to fit them. Need to think if I need more TRVs. Then I'm trying to see which might need external sensors as everyone says the stat in the TRV is a disaster. What should I zone where. etc. Have my own ideas but talking them out be helpful.

P.S. I know you're supposed to leave a rad without TRV for safety if you're not sure re bypass etc. Shoukd that be a rad without a TRV in each zone so? I assume if ground floor zone turns on incorrectly and all rads have a TRV which is closed then having an open rad in the top floor zone won't help?

deezell

legend99 wrote: »

.....P.S. I know you're supposed to leave a rad without TRV for safety if you're not sure re bypass etc. Shoukd that be a rad without a TRV in each zone so? I assume if ground floor zone turns on incorrectly and all rads have a TRV which is closed then having an open rad in the top floor zone won't help?

Nein, nein, 99, if all your rads have smart TRVs, then zones become redundant, so you just latch the zone valves open, as each rad (or slaved pair) is now a zone. A single open rad will provide the bypass for all zones, and a towel rail is ideal for this. I'll have a look back at the other stuff later and get back, time for a bit of science fiction..

digiman

This seems like a pretty decent deal here from different amazon sites:

Honeywell Home EVO Home Starter Kit with 2 x TRV Heads, White €229
https://www.amazon.es/Honeywell-evohome-thr99-C3112-termostato-conectable-control/dp/B0758N89X1/ref=sr_1_16?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=honeywell&qid=1606349264&sr=8-16

4 * Thermostats €179
https://www.amazon.de/-/en/Honeywell-evohome-THR0924HRT-Radiator-Controller/dp/B00MPJQFNU/ref=sr_1_12?dchild=1&keywords=honeywell&qid=1606347735&sr=8-12

1 * HW Sensor kit
https://www.amazon.co.uk/Evohome-ATF500DHW-Hot-Water-White/dp/B00R6621EY/ref=sr_1_3?dchild=1&keywords=honeywell+hot+water&qid=1606350139&sr=8-3

10 thermostats, Display, 2 relays and HW sensor for €680 seems like a pretty decent deal. Am I missing anything here, anything else I need to buy? I'm assuming the above items don't matter where in Europe they come from. Hopefully the spanish plug is easily swapped out, Oh and need to find the hot water kit I guess

deezell

digiman wrote: »

This seems like a pretty decent deal here from different amazon sites:

Honeywell Home EVO Home Starter Kit with 2 x TRV Heads, White €229
https://www.amazon.es/Honeywell-evohome-thr99-C3112-termostato-conectable-control/dp/B0758N89X1/ref=sr_1_16?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=honeywell&qid=1606349264&sr=8-16

4 * Thermostats €179
https://www.amazon.de/-/en/Honeywell-evohome-THR0924HRT-Radiator-Controller/dp/B00MPJQFNU/ref=sr_1_12?dchild=1&keywords=honeywell&qid=1606347735&sr=8-12

10 thermostats and the Display for €587 seems like a pretty decent deal. Am I missing anything here?

CS92 or ATF500DHW HW sensor kit. the former for vented cylinders, the latter for sealed.

legend99

deezell wrote: »

Nein, nein, 99, if all your rads have smart TRVs, then zones become redundant, so you just latch the zone valves open, as each rad (or slaved pair) is now a zone. A single open rad will provide the bypass for all zones, and a towel rail is ideal for this. I'll have a look back at the other stuff later and get back, time for a bit of science fiction..

So I need to buy 2 more TRVs to have the 13.

Just for everyone's attention, the Tado stuff Black Friday prices have kicked in. So TRVs down to 30 odd pounds each.

legend99

deezell wrote: »

Nein, nein, 99, if all your rads have smart TRVs, then zones become redundant, so you just latch the zone valves open, as each rad (or slaved pair) is now a zone. A single open rad will provide the bypass for all zones, and a towel rail is ideal for this. I'll have a look back at the other stuff later and get back, time for a bit of science fiction..

I feel a bit like Marty McFly here - he had a big problem thinking zone dimensionally too!

deezell

legend99 wrote: »

I feel a bit like Marty McFly here - he had a big problem thinking zone dimensionally too!

Speaking of Marty, this is hilarious
https://youtu.be/zI4lFjWoFqc
And
https://youtu.be/GIjDo-btyL0

legend99

deezell wrote: »

Speaking of Marty, this is hilarious
https://youtu.be/zI4lFjWoFqc
And
https://youtu.be/GIjDo-btyL0

That's hilarious. The poor guy though. So many diseases are so tough for so many people.

Come here so. If I had a full TRV set-up, then what happens to my thermostats etc? Like how would the TRVs turn on the heating? What do they talk to?! I should figure out the full optimal set-up now with the prices down!

Redlim

There's a new and supposedly improved Tado wireless starter kit which as part of the black Friday sale is available for £139.99 - link below. As per Amazon : "Improved version: Includes the new Wireless Receiver with an optimized user interface for an even easier installation". From what I can see this contains a "Tado° Wireless Temperature Sensor" and this new Wireless Receiver.

I had ordered the previous version the other day for £124.99 before this new kit came out but have now cancelled and ordered the new one instead along with a bunch of TRVs - all arriving earlier as I just signed up to a Prime trial! The older version includes in its components list a "Tado° Smart Thermostat" & "tado° Extension Kit". I'm hoping I haven't made a mistake changing to the new kit as it seems the thermostat might actually be the dumbed down temperature sensor and cannot control zone valves (??). Not sure if the new Wireless Receiver is much of an upgrade on the old Extension Kit apart from the supposedly easier installation. Since I'll have smart TRVs on all bar 2 rads maybe I don't need control over the zone valves?

New wireless kit:
https://www.amazon.co.uk/dp/B08LP1LS5T/ref=cm_sw_r_cp_apa_fabt1_dlC_B2ZVFbFS09K30


Old wireless kit :
https://www.amazon.co.uk/dp/B07VXBMC14/ref=cm_sw_r_cp_apa_fabt1_87ZVFbJP29KCG

deezell

legend99 wrote: »

....Come here so. If I had a full TRV set-up, then what happens to my thermostats etc? Like how would the TRVs turn on the heating? What do they talk to?! I should figure out the full optimal set-up now with the prices down!

You keep your stats as relays for rhe TRVs, they still turn the motorised valves and their boiler firing relay even if the plumbing part of the valve is latched open.
Starting from scratch with a full TRV system, you would not need zone valves, (except the HW one), and a single stat would suffice, wired directly to the boiler to fire it. This stat could be the temperature sensor also for a TRV or multiple TRVs, such as an open plan area with two or three rads, or as the sensor for a rad in a compromised location, near an open door or window.
I have three rads in a large T shaped hall and corridor, my main stat is located away from the front door around the hall corner in one corridor. If I went full TRV, I'd slave the three rad TRVs to it, which is what currently happens for the most part, as the air is well circulated in this area so no local hot spots. I'm quite content with single general zone, and a TRV to give the kitchen independent calling and closing off. TRV didn't work out in the main bedroom, too noisy for a certain light sleeper, it was sitting in the drawer after two nights. I could probably save a little if I capped off little used rooms with TRVs, but then they might become cold, damp and uninviting. The internal doors are always fully open anyway, so it's moot. Kitchen apart, the house is a big zone, and I kind of like it like that.

deezell

It seems Tado are reappraising the logical approach to their system architecture, which is to make all sensors wireless, and have the relay in a receiver. They were hamstrung by the fact that their system could not accommodate more than one ext kit, meaning only one wireless stat. They may be moving towards a similar setup to the opposition, with more than one receiver box for multiple wireless wall stats, as some house builds are over three floors these days, so three zones stats would be desirable, but difficult to retro wire two of them if wireless not an option.

savemejebus

Drayton Wiser Price Drops again on amazon. I think that this is a great bargain https://www.amazon.co.uk/gp/product/B075GNJ7ZN
(and easy enough to install that i could - with deezells advice - wire it up myself)

legend99

deezell wrote: »

You keep your stats as relays for rhe TRVs, they still turn the motorised valves and their boiler firing relay even if the plumbing part of the valve is latched open.
Starting from scratch with a full TRV system, you would not need zone valves, (except the HW one), and a single stat would suffice, wired directly to the boiler to fire it. This stat could be the temperature sensor also for a TRV or multiple TRVs, such as an open plan area with two or three rads, or as the sensor for a rad in a compromised location, near an open door or window.
I have three rads in a large T shaped hall and corridor, my main stat is located away from the front door around the hall corner in one corridor. If I went full TRV, I'd slave the three rad TRVs to it, which is what currently happens for the most part, as the air is well circulated in this area so no local hot spots. I'm quite content with single general zone, and a TRV to give the kitchen independent calling and closing off. TRV didn't work out in the main bedroom, too noisy for a certain light sleeper, it was sitting in the drawer after two nights. I could probably save a little if I capped off little used rooms with TRVs, but then they might become cold, damp and uninviting. The internal doors are always fully open anyway, so it's moot. Kitchen apart, the house is a big zone, and I kind of like it like that.

Ok so I have the following. I have 3 CH zones, ground floor, first floor and second floor - and 1 HW zone (although because there was never an actual programmer, only a 'dumb' timing clock, the live feed from the clock to the hot press where the top floor valve and HW valve is located is a single feed.

Ground floor zone has:
Kitchen: 2 rads,
Large (and bloody cold) living room: 1 rad
TV room: 1 rad
Hall: 1 rad
Current wired thermostat for the zone is in the hall

First floor zone has:
Bedroom 1: 1 rad plus ensuite which has 1 rad
Bedroom 2: 1 rad plus ensuite which has 1 rad
Bedroom 3: 1 rad
First floor landing: 1 rad
Current wired thermostat for the zone is in the first floor landing

Second floor zone has:
Bedroom 4: 1 rad
Bedroom 5: 1 rad
Main bathroom: 1 rad
Current wired thermostat for the zone is in the second floor landing (note no rad currently in this area)

So there are 14 rads (5 on ground floor, 6 on first floor, 3 on second floor)


I also have an unused extension kit. So what do you reckon my optimal set-up is?

masterboy123

Thanks so much. Just ordered it now.

I will follow up the advice from Deezell. It is supposed to be an easy swap from 3 zone EPH to 3 Zone Drayton Wiser.

savemejebus wrote: »

Drayton Wiser Price Drops again on amazon. I think that this is a great bargain https://www.amazon.co.uk/gp/product/B075GNJ7ZN
(and easy enough to install that i could - with deezells advice - wire it up myself)

loyatemu

that is a serious bargain on the Drayton kit, I paid more than double that amount.

it would be good to see some bulk discount on the TRV's as well

deezell

legend99 wrote: »

Ok so I have the following. I have 3 CH zones, ground floor, first floor and second floor - and 1 HW zone (although because there was never an actual programmer, only a 'dumb' timing clock, the live feed from the clock to the hot press where the top floor valve and HW valve is located is a single feed...
....So there are 14 rads (5 on ground floor, 6 on first floor, 3 on second floor)
I also have an unused extension kit. So what do you reckon my optimal set-up is?

Install the ext kit next to the top floor valves, connect the HW valve and top floor CH valve, assign the ext kit to the top floor stat. You now will have seperate control on the app for HW, and you can relocate the top floor stat wirelessly to a room that actually has a radiator, one of the beds most likely.
If your rooms are difficult to heat, such as the freezing lounge, which I presume is slower to heat than other rooms in that zone, then you could add additional insulation to this room, internal insulated wall boards if possible. Check for air leaks, excessive air through the vent, windows which dont seal, an open unused chimney. Maybe the internal walls are already plasterboard on studs and are open at the edge inside the external wall vent, very common, allowing the inside of the boards to cool rapidly. They may not be sealed at the top either, venting heat to the first floor joists space.
You might need a bigger convection radiator in this room, to make sure it gets its share of the heat, but anything you can do to prevent heat loss, check this out First.

championc

So £120.99 for Tado Quad packs of Smart TRV's

https://www.amazon.co.uk/tado%C2%B0-Radiator-Thermostat-Vertical-mounting/dp/B07FYS7GC4/ref=mp_s_a_1_1_sspa?dchild=1&qid=1606398011

baldshin

deezell wrote: »

He's just wired it as a fully pumped or S plan 2 zone system. He's probably unaware that your 2 zone system is a gravity system. He's wired CH to fire the boiler, (black wire to 3) and HW to drive the pump (grey wire to 6). You need to remove black from 3. and move the grey from 6 to 3, plus add a link from 3 to 4. Move brown from 5 to 6, and connect black to 5. This will fulfil the wiring on my diagram.
I notice on the image that he has connnected a single wire to the 12v T1 connection. The T1 T2 connectors are there to supply 12v back up the old isolated wire pair to your original mechanical stat location in order to supply 12v to power the Nest without the need of the mains adaptor. I'm not sure why he has only connected one terminal, T1, and used the other wire to connect the earth terminal. If your Nest is installed at the old stat location without the mains adaptor it won't charge, and will run out of power. Unless the T2 terminal is internally grounded to earth, I don't see how it can power the stat on the wall, as the 12v is supplied from the T1 and T2.

Just putting out a massive thank you to Deezell. Your help and advice on this forum is astounding, always so detailed and helpful.

Managed to finally get this running myself as expected using your guide. Messaged the expert, who messaged me this morning after I complained to the company, telling him he's no longer needed, and even sent him the diagram so he knows in future for systems like this.

Have requested a partial refund from the company, as to be fair he still did a good bit of the work, including mounting of the units and providing the wallplate.

Edit-
I spoke too soon. While almost everything is working as expected, I've just experienced the heat staying on again despite the Nest being off. Looks like the old analogue wall dials are still somewhat in control on occasion. When I turned them down, the heat went off. They had been left in situ turned right up, supposedly then the Nest would have full control. Is there an easy way to decommission these so that only the Nest has control of the boiler?

legend99

deezell wrote: »

Install the ext kit next to the top floor valves, connect the HW valve and top floor CH valve, assign the ext kit to the top floor stat. You now will have seperate control on the app for HW, and you can relocate the top floor stat wirelessly to a room that actually has a radiator, one of the beds most likely.
If your rooms are difficult to heat, such as the freezing lounge, which I presume is slower to heat than other rooms in that zone, then you could add additional insulation to this room, internal insulated wall boards if possible. Check for air leaks, excessive air through the vent, windows which dont seal, an open unused chimney. Maybe the internal walls are already plasterboard on studs and are open at the edge inside the external wall vent, very common, allowing the inside of the boards to cool rapidly. They may not be sealed at the top either, venting heat to the first floor joists space.
You might need a bigger convection radiator in this room, to make sure it gets its share of the heat, but anything you can do to prevent heat loss, check this out First.

Given that I have/will have after next week, a TRV for each rad, does that mean something different in terms of set-up? In terms of the 'smartest' way to approach the smart set-up?

Front room. It's a big room - probably well over 20 square meters. Does have open chimney and rad isn't huge alright. Just a single, not double, rad. Vent in window won't budge in terms of closing. But I always assume they had done something deliberately as there is a chimney and that is the only vent in the room so think the regs require a vent? All external walls have been pumped with beads - and the internal walls are already plasterboard with insulation on the back. I know this from trying to hang bloody curtain rails!

SouthWesterly

Are there any pros/cons with getting drayton over tado?

deezell

baldshin wrote: »

.... Looks like the old analogue wall dials are still somewhat in control on occasion. When I turned them down, the heat went off. They had been left in situ turned right up, supposedly then the Nest would have full control. Is there an easy way to decommission these so that only the Nest has control of the boiler?

Have you wall thermostats in addition to the Grasslin? How many? Did the installer remove the Grasslin?. It was the timer unit, I'd assumed you had no wall stats. If you have more than one stat, it sounds like you have zoned heating, with Zone valves. If it works properly with these stats turned down, then there's some other source of switched power being sent to fire the boiler, just leave them down and see does the system work as it should.

deezell

legend99 wrote: »

Given that I have/will have after next week, a TRV for each rad, does that mean something different in terms of set-up? In terms of the 'smartest' way to approach the smart set-up?

Front room. It's a big room - probably well over 20 square meters. Does have open chimney and rad isn't huge alright. Just a single, not double, rad. Vent in window won't budge in terms of closing. But I always assume they had done something deliberately as there is a chimney and that is the only vent in the room so think the regs require a vent? All external walls have been pumped with beads - and the internal walls are already plasterboard with insulation on the back. I know this from trying to hang bloody curtain rails!

I've no vent in my front room, I don't light the fire except at Xmas, and I have a cap on the chimney rest of the year. It's a huge 7 by 5m room, but stays warm with a single panel rad, 2.4m by 0.6m. It's up to you to fit a closing vent, if you don't light the fire. You can get an inflatable flue baloon also, stops the heat loss.
Also check if your boiler flow temperature is not set too low, it might need to be increased to get more output from your existing rad. High 60s° is normal to get a good output from the panels.
As regards all TRVs, you can latch open the zone valves permanently, which will create a single circulation zone. The zone motors will still operate to trigger their boiler relays. You can leave one rad or a towel rail open to act as a bypass for all zones. Try grouping rads under a single zone to avoid having too many zones to manage.

raytaxi

Deezell looking a bit of advice have a 3 zone ember, thinking of swapping to the drayton kit two zone plus hot water. How will I control hot water as ember has a thermostat on tank and hits temp turns off. How would it work with drayton will it just keep heating or off at boiler limit.

deezell

raytaxi wrote: »

Deezell looking a bit of advice have a 3 zone ember, thinking of swapping to the drayton kit two zone plus hot water. How will I control hot water as ember has a thermostat on tank and hits temp turns off. How would it work with drayton will it just keep heating or off at boiler limit.

I presume you're referring to the Ember RFC wireless cylinder stat? Unfortunately this is unique to the Ember controller. For most other systems the choice is a wired mechanical stat, which is perfectly adequate for HW control and to prevent the boiler limiting. You could use a Sonoff relay with temperature probe to replicate the function of the Ember RFC, but it would have to accessed from its own app, and woul need to be harf wired at or clise to the cylinder. I'm not sure why you would need to remotely monitor or adjust HW temperature. Use a mechanical cylinder stat, set snd forget.